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Sample records for donor immunoassay cedia

  1. Establishment of new cloned enzyme donor immunoassays (CEDIA) for haloperidol and bromperidol.

    PubMed

    Yasui-Furukori, Norio; Saito, Manabu; Furukori, Hanako; Inoue, Yoshimasa; Someya, Toshiyuki; Kaneko, Sunao; Tateishi, Tomonori

    2004-06-01

    The authors have developed and verified the precision and accuracy of new automated cloned enzyme donor immunoassays (CEDIA) for haloperidol and bromperidol, and cross-validations have been performed with conventional semiautomated EIA kits (MARKIT-M) and high-performance liquid chromatographic (HPLC) methods. The CEDIA method provides a quick (about 10 minutes) assay for haloperidol or bromperidol, requiring no serum/plasma pretreatment or predilution. The CEDIA haloperidol/bromperidol assay showed little or no cross reactivity with either their metabolites or many drugs commonly coprescribed. MARKIT-M revealed considerable cross reactivity values proportional to the spiked amounts of reduced metabolites. Precision, accuracy, recovery, and linearity testing for the CEDIA assay were all sufficient for clinical use. Significant linear correlations were found between CEDIA and HPLC in measuring haloperidol (CEDIA = 1.06 x HPLC + 0.869; n = 44, rs = 0.913, P < 0.001) and bromperidol (CEDIA = 1.06 x HPLC + 0.606; n = 56, rs = 0.914, P < 0.001) concentrations. This study has, therefore, demonstrated that the CEDIA assay has a quick run time with high precision and accuracy, and this method is a useful tool for the TDM of haloperidol or bromperidol. PMID:15167638

  2. Comparison of LUCIO®-direct ELISA with CEDIA immunoassay for 'zero tolerance' drug screening in urine as required by the German re-licensing guidelines.

    PubMed

    Agius, Ronald; Nadulski, Thomas; Kahl, Hans-Gerhard; Dufaux, Bertin

    2013-06-01

    The performance of the previously validated LUCIO(®)-Direct-enzyme linked immunosorbent assay (direct ELISA) screening tests according to forensic guidelines is compared to that of cloned enzyme donor immunoassays (CEDIA) test for drugs of abuse in urine as defined in the new re-licensing German medical and psychological assessment (MPA) guidelines. The MPA screening cut-offs correspond to 10 ng/ml 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), 50 ng/ml amphetamine and designer amphetamines, 25 ng/ml morphine, codeine and dihydrocodeine, 30 ng/ml benzoylecgonine, 50 ng/ml methadone metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and metabolites of diazepam, oxazepam, bromazepam, alprazolam, flunitrazepam and lorazepam at 50 ng/ml. Average relative sensitivities and relative specificities were 99.7 % and 98.4 % for direct ELISA and 66 % and 91.4 % for CEDIA, respectively. PMID:23349145

  3. Buprenorphine detection in urine using liquid chromatography-high-resolution mass spectrometry: comparison with cloned enzyme donor immunoassay (ThermoFisher) and homogeneous enzyme immunoassay (immunalysis).

    PubMed

    Belsey, Sarah L; Couchman, Lewis; Flanagan, Robert J

    2014-09-01

    A sensitive liquid chromatographic-high-resolution mass spectrometric (LC-HR-MS) assay for buprenorphine and its urinary metabolites has been developed that requires minimal sample preparation. The results obtained have been compared with those given by (i) cloned enzyme donor immunoassay (CEDIA) and (ii) homogeneous enzyme immunoassay (HEIA) in the analysis of patient urines submitted for buprenorphine analysis. Centrifuged urine (100 µL) was diluted with internal standard solution (25 µL) + LC eluent (875 µL), and 50 µL of the prepared sample were analyzed (Accucore Phenyl-Hexyl column). MS detection was in alternating positive and negative mode using heated electrospray ionization (ThermoFisher Q Exactive). Intra- and inter-assay accuracy and precision were 104-128 and <11%, respectively, at 5 µg/L. Limits of detection were 1.3 µg/L (buprenorphine, norbuprenorphine and buprenorphine glucuronide) and 2.5 µg/L (norbuprenorphine glucuronide). Immunoassay sensitivity and selectivity were 97 and 100% (HEIA) and 99 and 84% (CEDIA), respectively, compared with LC-HR-MS. In 120 patient urines, norbuprenorphine glucuronide was easily the most abundant analyte except when adulteration with buprenorphine had occurred. The median immunoreactive buprenorphine species present (unhydrolysed urine) were 7.5 and 13% for HEIA and CEDIA, respectively. However, codeine, dihydrocodeine, morphine and morphine-3-glucuronide did not interfere in the HEIA assay. PMID:24925983

  4. Cross-reactivity of the CEDIA buprenorphine assay in drugs-of-abuse screening: influence of dose and metabolites of opioids

    PubMed Central

    Berg, Jon Andsnes; Schjøtt, Jan; Fossan, Kjell O; Riedel, Bettina

    2015-01-01

    Purpose The cloned enzyme donor immunoassay (CEDIA) for buprenorphine is applied for both urine drugs-of-abuse screening and compliance monitoring. Sensitivity, specificity, and optimal cutoff of this assay have differed between studies. This may indicate that cross-reactivity has to be taken into account during assay evaluation. We therefore investigated the performance of the CEDIA buprenorphine assay for use in our patient population and explored the impact of cross-reactivity on assay accuracy. Methods The CEDIA buprenorphine assay and high-performance liquid chromatography–tandem mass spectrometry were employed to analyze drugs-of-abuse in urine samples from a healthy drug-naïve male volunteer after intake of two tablets of a prescription drug containing 400 mg paracetamol +30 mg codeine phosphate, and in urine samples (n=2,272) from drug-addicted patients. Receiver operating characteristic analyses were performed to express the diagnostic accuracy of the CEDIA buprenorphine assay. Results CEDIA buprenorphine was positive in one urine sample from the drug-naïve person after intake of the prescription drug. Twenty-five (1.1%) of the patient urine samples were positive for buprenorphine by CEDIA, but negative by high-performance liquid chromatography–tandem mass spectrometry. Codeine, morphine, and their respective metabolites were prevalent in samples that were false positive for buprenorphine. The specificity of the CEDIA buprenorphine assay increased to 99.7% when the cutoff was increased from 5 ng/mL to 10 ng/mL. Conclusion Intake of a therapeutic dose of codeine can yield a false-positive CEDIA buprenorphine result. Additive effects from metabolites of codeine contribute to cross-reactivity in concentrations much lower than listed in the manufacturer’s cross-reactivity guide. Raising the cutoff from 5 ng/mL to 10 ng/mL increased the diagnostic accuracy. Clinicians should be informed about the risk of false-positive results with the CEDIA

  5. Improved buprenorphine immunoassay performance after urine treatment with β-glucuronidase.

    PubMed

    Snyder, Marion L; Darragh, Alicia; Flood, James G; Jones, Jenny; Ropar, Kaitlin; Jarolim, Petr; Melanson, Stacy E F

    2014-01-01

    Buprenorphine (BUP), a semi-synthetic opioid analgesic, is increasingly prescribed for the treatment of chronic pain and opioid dependence. Urine immunoassay screening methods are available for monitoring BUP compliance and misuse; however, these screens may have poor sensitivity or specificity. We evaluated whether the pretreatment of urine with β-glucuronidase (BG) improves the sensitivity and overall accuracy of three BUP enzyme immunoassays when compared with liquid chromatography-tandem mass spectrometry (LC-MS-MS). Urine samples sent to our laboratories for BUP testing (n = 114) were analyzed before and after BG pretreatment by cloned enzyme donor immunoassay (CEDIA), enzyme immunoassay (EIA) and homogenous EIA (HEIA) immunoassays using a common 5 ng/mL cutoff. Total BUP and norbuprenorphine (NBUP) concentrations were measured by LC-MS-MS as the reference method. Urine BG pretreatment improved EIA, HEIA and CEDIA sensitivities from 70, 82 and 94%, respectively, to 97% for each of the three methods, when compared with LC-MS-MS. While the specificity of the EIA and HEIA remained 100% after BG pretreatment, the specificity of the CEDIA decreased from 74 to 67%. Urine pretreatment with BG is recommended to improve sensitivity of the EIA and HEIA BUP screening methods. PMID:24802159

  6. Evaluation of the diagnostic performance of the Boehringer Mannheim CEDIA LSD assay.

    PubMed

    Verstraete, A G; Steyaert, S

    1998-01-01

    The precision and the diagnostic performance of the Boehringer Mannheim CEDIA DAU LSD assay was evaluated. The assay was performed in the semi-quantitative mode on a Hitachi 917 analyzer. Within-run coefficients of variation (CVs) of the semiquantitative values for 0.25 and 1.0 ng/mL were 11.2 and 6.2%, respectively. Day-to-day CVs for the same concentrations were 12.6 and 8.6%. We analyzed 318 urine samples by CEDIA, DPC Coat-A-Count RIA and Behring EMIT II. Confirmation was performed by GC-MS, after extraction on Bond Elut Certify columns. Two hundred sixty-three samples were negative by all methods. Twenty-five samples were positive by all immunoassays, 19 of which were confirmed by gas chromatography-mass spectrometry (GC-MS). One sample was falsely negative by CEDIA. Three samples were positive by EMIT and CEDIA, but negative by RIA and GC-MS. Twenty-six samples were positive by EMIT alone, but they were not confirmed by GC-MS. The LSD CEDIA assay seems to be less specific than DPC RIA but more specific than the EMIT LSD assay. PMID:9847012

  7. An ImmunoChip prototype for simultaneous detection of antiepileptic drugs using an enhanced one-step homogeneous immunoassay1 2 3 4

    PubMed Central

    Yang, Xiaoyun; Janatova, Jarmila; Juenke, JoEtta M.; McMillin, Gwendolyn A.; Andrade, Joseph D.

    2007-01-01

    The development and characterization of a one-step homogeneous immunoassay-based multi-well ImmunoChip is reported for the simultaneous detection and quantitation of antiepileptic drugs (AEDs). The assay platform utilizes a Cloned Enzyme Donor Immunoassay (CEDIA), and a Beta-Glo assay system for generation of bioluminescent signal. Results of the one-step CEDIA for three AEDs (CBZ, carbamazepine; PHT, phenytoin; VPA, valproic acid), in the presence of serum, correlate well with the values determined by Fluorescence Polarization Immunoassay. CEDIA intra-assay and inter-assay coefficients of variation are lower than 10%. A microfabrication process, xurography, was utilized to produce the multi-well ImmunoChip. Assay reagents were dispensed, and lyophilized, in a three-layer pattern. The multi-well ImmunoChip prototype was used to detect and quantify AEDs in serum samples containing all three drugs. Luminescent signals generated from each well were recorded with a Charged Coupled Device (CCD) camera. The assays performed on an ImmunoChip were fast (5 min), requiring only small volumes of both the reagents (< 1 μl per well) and the serum sample. The ImmunoChip assay platform described herein may be well suited for therapeutic monitoring of drugs and metabolites at the point-of-care. PMID:17448436

  8. Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays are analytical methods that employ antibodies or molecules derived from antibodies for the essential binding reactions. The choice of immunoassay system for food safety analysis depends on the analyte, the matrix, and the requirements of the analysis (speed, throughput, sensitivity, spe...

  9. Immunoassays

    NASA Astrophysics Data System (ADS)

    Hsieh, Y.-H. Peggy

    Immunochemistry is a relatively new science that has developed rapidly in the last few decades. One of the most useful analytical developments associated with this new science is immunoassay. Originally immunoassays were developed in medical settings to facilitate the study of immunology, particularly the antibody-antigen interaction. Immunoassays now are finding widespread applications outside the clinical field because they are appropriate for a wide range of analytes ranging from proteins to small organic molecules. In the food analysis area, immunoassays are widely used for chemical residue analysis, identification of bacteria and viruses, and detection of proteins in food and agricultural products. Protein detection is important for determination of allergens and meat species content, seafood species identification, and detection of genetically modified plant tissues. While immunoassays of all formats are too numerous to cover completely in this chapter, there are several procedures that have become standard for food analysis because of their specificity, sensitivity, and simplicity.

  10. Comparison of performance of two Treponema pallidum automated chemiluminescent immunoassays in blood donors.

    PubMed

    Sommese, Linda; Sabia, Chiara; Esposito, Antonella; Iannone, Carmela; Montesano, Maria Lourdes; Napoli, Claudio

    2016-01-01

    The recrudescence of syphilis is leading to the development of new serological tests. The goal of this study was to compare the performance of the more recent Elecsys Syphilis assay, the Electro Chemiluminescence Immunoassay (ECLIA), with the former Architect Syphilis TP assay, the Chemiluminescent Microparticle Immunoassay (CMIA), for the detection of antibodies against Treponema pallidum in blood donors. Serum samples of 5543 voluntary blood donors were screened in parallel with two tests. All repeatedly reactive (RR) samples by one or both assays were further analysed for confirmation by immmunoblot INNO-LIA and TPHA. Of 32 RR samples by CMIA, 21 were confirmed positive; of 21 RR samples by ECLIA, 20 were confirmed positive. The sensitivities of CMIA and ECLIA were 100% and 95.24% (95% CI = 85.71-100), respectively, not significant (p > 0.05). The specificity and predictive positive value (PPV) of CMIA were 99.86% (95% CI = 99.74-99.94) and 72.41%, respectively, while the specificity and PPV of ECLIA were both 100%, being statistically significant (p = 0.01 for both). The overall agreement was 99.80% and the Cohen's kappa coefficients was 0.79. In conclusion, the recent Elecsys Syphilis assay could represent another reliable assay for blood donor screening. PMID:27030921

  11. Determination of Babesia microti seroprevalence in blood donor populations using an investigational enzyme immunoassay

    PubMed Central

    Levin, Andrew E; Williamson, Phillip C; Erwin, James L; Cyrus, Sherri; Bloch, Evan M; Shaz, Beth H; Kessler, Debra; Telford, Sam R; Krause, Peter J; Wormser, Gary P; Ni, Xiaoyan; Wang, Haihong; Krueger, Neil X; Caglioti, Sally; Busch, Michael P

    2014-01-01

    Background Transfusion-transmitted babesiosis caused by Babesia microti has emerged as a significant risk to the US blood supply. This study estimated the prevalence of B. microti antibodies in blood donors using an investigational enzyme immunoassay (EIA). Study Design and Methods A peptide-based EIA that detects both immunoglobulin (Ig)G and IgM antibodies to B. microti was developed and validated. Donor samples randomly selected from areas defined as high-risk endemic, lower-risk endemic, and nonendemic for B. microti were deidentified and tested using the investigational EIA. Samples that were EIA repeat reactive were further tested by B. microti immunofluorescent assay (IFA), polymerase chain reaction (PCR) on red blood cell lysates, and peripheral blood smear examination. A random subset of 1272 samples from high-risk endemic areas was tested by IFA, PCR, and peripheral blood smear in parallel with EIA. Results Among 15,000 donations tested with the investigational B. microti EIA, EIA repeat-reactive rates were 1.08% (54/5000) in a high-risk endemic area, 0.74% (37/5000) in a lower-risk area, and 0.40% (20/5000) in a nonendemic area. After application of a revised cutoff, these values were reduced to 0.92%, (46/5000), 0.54% (27/5000), and 0.16% (8/5000). Overall concordance between EIA and IFA among donor samples was 99.34%. One seropositive sample was positive by PCR. Conclusion The seroprevalence of B. microti in blood donors in a high-risk area measured by an investigational EIA was approximately 1%. The EIA shows promise as an efficient high-throughput blood donor screening assay for B. microti. PMID:24995863

  12. New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods.

    PubMed

    Kuhns, Mary C; Busch, Michael P

    2006-01-01

    Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to

  13. In Situ Generation of Electron Donor to Assist Signal Amplification on Porphyrin-Sensitized Titanium Dioxide Nanostructures for Ultrasensitive Photoelectrochemical Immunoassay.

    PubMed

    Shu, Jian; Qiu, Zhenli; Zhuang, Junyang; Xu, Mingdi; Tang, Dianping

    2015-10-28

    An ultrasensitive photoelectrochemical (PEC) immunoassay protocol for quantitative detection of low-abundant proteins at a low potential was designed by utilizing porphyrin-sensitized titanium dioxide (TiO2) nanostructures. Experimental results demonstrated that the water-soluble 5,10,15,20-tetra(4-sulfophenyl)-21H,23H-porphyrin (TSPP) could be bound onto titanium dioxide via the sulfonic group. TSPP-sensitized TiO2 nanostructures exhibited better photoelectrochemical responses and stability in comparison with TiO2 nanoparticles alone under continuous illumination. Using carcinoembryonic antigen (CEA) as a model analyte, a typical PEC immunosensor by using TSPP-TiO2 as the affinity support of anti-CEA capture antibody (Ab1) to facilitate the improvement of photocurrent response was developed. Bioconjugates of secondary antibody and glucose oxidase with gold nanoparticles (Ab2/GOx-AuNPs) was introduced by an antigen-antibody immunoreaction. AuNP acted as a powerful scaffold to bind with bioactive molecules, while GOx catalyzed glucose to in situ generate hydrogen peroxide (H2O2). The generated H2O2 as a sacrificial electron donor could be oxidized by the photogenerated holes to assist the signal amplification at a low potential under light excitation, thus eliminating interference from other species coexisting in the samples. Under optimal conditions, the PEC immunosensor showed a good linear relationship ranging from 0.02 to 40 ng mL(-1) with a low detection limit of 6 pg mL(-1) CEA. The precision, reproducibility, and specificity were acceptable. In addition, the method accuracy was also evaluated for quantitatively monitoring human serum samples, giving results matching with the referenced CEA ELISA kit. PMID:26451956

  14. Determination of designer drug cross-reactivity on five commercial immunoassay screening kits.

    PubMed

    Regester, Laura E; Chmiel, Jeffrey D; Holler, Justin M; Vorce, Shawn P; Levine, Barry; Bosy, Thomas Z

    2015-03-01

    The detection of new designer drugs is often a difficult issue in forensic urine drug testing as immunoassays are the primary screening methodology for drugs of abuse in many of these laboratories. Cross-reactivity of compounds with immunoassay kits can either aid or complicate the detection of a variety of drug and drug metabolites. For instance, emerging designer drugs that share structural similarities to amphetamines and phencyclidine (PCP) have the potential to cross-react with assays designed to detect these compounds. This study evaluates the cross-reactivity of five commercially available immunoassay reagent kits for 94 designer drugs on a Roche/Hitachi Modular P automated screening instrument. The compounds used in this study are grouped by structural class as follows: 2,5-dimethoxyamphetamines, 2C (2,5-dimethoxyphenethylamines), β-keto amphetamines, substituted amphetamines, piperazines, α-pyrrolidinopropiophenones, tryptamines and PCP analogs. A drug concentration of 100 µg/mL was used to determine cross-reactivity for each assay and resulted in the following positive rates: Microgenics DRI(®) Ecstasy enzyme assay (19%), Microgenics DRI(®) Phencyclidine enzyme assay (20%), Lin-Zhi Methamphetamine enzyme immunoassay (39%), Siemens/Syva(®) EMIT(®)II Plus Amphetamines assay (43%) and CEDIA(®) DAU Amphetamine/Ecstasy assay (57%). Of the 94 designer drugs tested, 14% produced a negative response for all five kits. No designer drug used in this study generated a positive result for all five immunoassay kits. PMID:25492523

  15. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India

    PubMed Central

    Arora, Satyam; Doda, Veena

    2016-01-01

    Background: The use of elevated signal-to-cut off ratios (S/CO) as an alternate to further supplemental testing (i.e., RIBA) has been included in the guidelines provided by the Centres for Disease Control and Prevention for HCV diagnostic purposes since 2003. With availability of screening by NAT and non availability of RIBA, further confirmation of HCV infection has been possible at the molecular level (RNA). Aims: To study the role of S/CO ratios of anti hepatitis C virus antibody detection by enzyme immunoassays (EIA) along with ID-NAT for screening of whole blood donors. Methods: In this study we reviewed the donor screening status for anti HCV from January 2013 to May 2014. All the donations were screened for anti HCV with fourth generation ELISA (BioRad Monolisa Ag-Ab Ultra) as well as with ID NAT (Procleix Ultrio). The S/CO ratio of all the anti-HCV reactive samples were analysed for their presence of HCV RNA. Results: On screening 21,115 donors for HCV, 83 donors (0.39%) were found reactive on pilot tube and repeat plasma bag testing (S/Co ratio ≥1) by ELISA. 41 donors were HCV RNA reactive with ID-NAT. 4 samples out of 41 were NAT yields and 37 were concordant reactive with ELISA. The S/Co ratio of anti-HCV reactive samples ranged from 0.9-11.1 [mean = 5.1; SD ± 2.9] whereas S/Co ratio of anti HCV and NAT reactive samples (concordant positives) ranged from 4.1-11.1 [mean 7.3]. In our analysis we found that S/CO ratio of 4 showed positive predictive value (PPV) and sensitivity of 100%. Summary/Conclusions: Our study showed that S/CO of 4 for anti HCV on ELISA would have maximum positive predictive value of having donor with HCV RNA. S/CO ratio of 4 is very close to 3.8 which was the CDC guideline. The presence of anti-HCV does not distinguish between current or past infections but a confirmed anti-HCV-positive result indicates the need for counseling and medical evaluation for HCV infection. PMID:27011676

  16. Effects of Stealth adulterant on immunoassay testing for drugs of abuse.

    PubMed

    Cody, J T; Valtier, S

    2001-09-01

    Stealth is an adulterant advertised as being undetectable by adulteration tests. It has been described as peroxidase and peroxide, which, when added to urine samples, are intended to prevent a positive drug test. Characterization of the effect of Stealth on urine samples and immunoassay results was undertaken to assist in detection of this adulterant. Stealth was added to a number of urine matrices, and various parameters were evaluated including pH, specific gravity, color, creatinine, chloride, urea, blood, glucose, and nitrite. Samples were spiked with THC acid metabolite, benzoylecgonine, morphine, secobarbital, PCP, amphetamine, and lysergic acid diethylamide (LSD) then tested by Roche OnLine and Microgenics CEDIA immunoassay reagents. Results of these analyses showed Stealth did not cause the urine sample to exceed any of the monitored parameters including those routinely used in drug-testing laboratories that would indicate adulteration of a sample. It did, however, cause samples positive for the marijuana metabolite (11-nor-delta9-tetrahydrocannibinol-9-carboxylic acid), LSD, and opiate (morphine) at 125-150% of cutoff to screen negative by immunoassay. Adulterating an authentic positive sample provided by a marijuana user caused that sample to screen negative using these immunoassay reagents as well. PMID:11550822

  17. Immunoassays in Biotechnology

    EPA Science Inventory

    Immunoassays have broad applications for a wide variety of important biological compounds and environmental contaminants. Immunoassays can detect the presence of an antigen in the human body, a pollutant in the environment, or a critical antibody in a patient’s serum to develop a...

  18. Updates in immunoassays: parasitology.

    PubMed

    Josko, Deborah

    2012-01-01

    Although most clinical laboratories use microscopy and routine O&P procedures when identifying parasitic infections, there are several parasites that are better detected through serological means. Toxoplasma, Giardia, and Cryptosporidium were discussed along with immunoassays used for their detection. Immunoassays provide quick results and are less labor intensive than specimen concentration and slide preparation for microscopic examination. These assays are easy to use and provide sensitive and specific results. Some clinical laboratories no longer perform O&Ps in house and refer specimens to reference laboratories for evaluation. By using immunoassays, some of the more common parasites can be identified in a timely manner reducing turn-around times. Some controversy exists over the use of IIF and EIA tests used for ANA testing along with measuring CRPs and PCT as predictors of bacterial sepsis and septic shock. Regardless of the methodology discussed in this series of articles, there are pros and cons to the various immunoassays available. Determining the most appropriate assay based on patient population and volume is governed by the institution and its patients' needs. In conclusion, immunoassays, whether manual or automated, are easy to use, cost effective and allow the medical laboratory professional to provide quick and accurate results to the clinician so the most appropriate treatment can be administered to the patient. The ultimate goal of healthcare professionals is to provide the highest quality of medical care in a timely manner. The use of immunoassays in the clinical laboratory allows the healthcare team to successfully achieve this goal. PMID:22953520

  19. Updates in immunoassays: bacteriology.

    PubMed

    Josko, Deborah

    2012-01-01

    There are many immunoassays available that provide rapid, accurate and sensitive results. The intent of this article was to provide a brief overview of some of the products and methodologies available for clinical use and to discuss some of the principles behind the methodology and instrumentation. In the area of infectious disease, the use of immunoassays ensures rapid turnaround times that will result in the administration of prompt, accurate treatment for the patient. Ultimately, this will improve overall patient outcomes while possibly decreasing the costs associated with increased hospital stay. In conclusion, immunoassays are essentially easy to perform, cost-effective, produce highly sensitive and specific results, and allow the medical laboratory professional the ability to report accurate results in a timely manner. PMID:22953518

  20. Hydrogel nanoparticle based immunoassay

    DOEpatents

    Liotta, Lance A; Luchini, Alessandra; Petricoin, Emanuel F; Espina, Virginia

    2015-04-21

    An immunoassay device incorporating porous polymeric capture nanoparticles within either the sample collection vessel or pre-impregnated into a porous substratum within fluid flow path of the analytical device is presented. This incorporation of capture particles within the immunoassay device improves sensitivity while removing the requirement for pre-processing of samples prior to loading the immunoassay device. A preferred embodiment is coreshell bait containing capture nanoparticles which perform three functions in one step, in solution: a) molecular size sieving, b) target analyte sequestration and concentration, and c) protection from degradation. The polymeric matrix of the capture particles may be made of co-polymeric materials having a structural monomer and an affinity monomer, the affinity monomer having properties that attract the analyte to the capture particle. This device is useful for point of care diagnostic assays for biomedical applications and as field deployable assays for environmental, pathogen and chemical or biological threat identification.

  1. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W.; Williams, Peter; Krone, Jennifer Reeve

    2005-12-13

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  2. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2007-12-04

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  3. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2013-07-16

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  4. IMMUNOASSAY HUMAN EXPOSURE STUDIES

    EPA Science Inventory

    The Human Exposure Research Branch has developed several enzyme-linked immunosorbent assay (ELISA) methods to support human exposure assessment studies. Immunoassays to detect low levels (<10 ng/mL) of chlorpyrifos in food, track-in dirt and house dust have been applied to sam...

  5. Updates in immunoassays: virology.

    PubMed

    Josko, Deborah

    2012-01-01

    Virus identification is a challenge to the clinical microbiologist since growing viruses in traditional cell culture is labor intensive, time consuming, and subject to contamination. The advent of rapid and automated immunoassays has eliminated this problem by generating positive results in minutes to hours. For example, testing for infectious mononucleosis can yield a positive result in 3-8 minutes as seen with the Beckman Coulter, Inc. ICON Mono test or in 5-15 minutes with the MONO Mononucleosis Rapid Test Device marketed by ACON Laboratories, Inc. Fully automated immunoassay analyzers provide fast, accurate, sensitive results that aid in a prompt and accurate diagnosis for the patient. Turnaround times are shortened, allowing for timely medical intervention and treatment. The priority in any hospital or medical facility is to treat the patient as quickly and appropriately as possible. By using immunoassays, clinical laboratory professionals are able to report out correct results in a timely manner, ensuring overall positive patient outcomes and improved quality of healthcare. PMID:22953519

  6. Automated imatinib immunoassay

    PubMed Central

    Beumer, Jan H.; Kozo, Daniel; Harney, Rebecca L.; Baldasano, Caitlin N.; Jarrah, Justin; Christner, Susan M.; Parise, Robert; Baburina, Irina; Courtney, Jodi B.; Salamone, Salvatore J.

    2014-01-01

    Background Imatinib pharmacokinetic variability and the relationship of trough concentrations with clinical outcomes have been extensively reported. Though physical methods to quantitate imatinib exist, they are not widely available for routine use. An automated homogenous immunoassay for imatinib has been developed, facilitating routine imatinib testing. Methods Imatinib-selective monoclonal antibodies, without substantial cross-reactivity to the N-desmethyl metabolite or N-desmethyl conjugates, were produced. The antibodies were conjugated to 200 nm particles to develop immunoassay reagents on the Beckman Coulter AU480™ analyzer. These reagents were analytically validated using Clinical Laboratory Standards Institute protocols. Method comparison to LC-MS/MS was conducted using 77 plasma samples collected from subjects receiving imatinib. Results The assay requires 4 µL of sample without pre-treatment. The non-linear calibration curve ranges from 0 to 3,000 ng/mL. With automated sample dilution, concentrations of up to 9,000 ng/mL can be quantitated. The AU480 produces the first result in 10 minutes, and up to 400 tests per hour. Repeatability ranged from 2.0 to 6.0% coefficient of variation (CV), and within-laboratory reproducibility ranged from 2.9 to 7.4% CV. Standard curve stability was two weeks and on-board reagent stability was 6 weeks. For clinical samples with imatinib concentrations from 438 – 2,691 ng/mL, method comparison with LC-MS/MS gave a slope of 0.995 with a y-intercept of 24.3 and a correlation coefficient of 0.978. Conclusion The immunoassay is suitable for quantitating imatinib in human plasma, demonstrating good correlation with a physical method. Testing for optimal imatinib exposure can now be performed on routine clinical analyzers. PMID:25551407

  7. Mass spectrometric immunoassay

    SciTech Connect

    Nelson, R.W.; Krone, J.R.; Bieber, A.L.; Williams, P.

    1995-04-01

    A new, general method of immunoassay is demonstrated. The approach is based on the microscale immunoaffinity capture of target antigens followed by mass-specific identification and quantitation using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Immunoaffinity capture of antigens effectively overcomes signal suppression effects typically encountered during traditional matrix-assisted laser desorption/ionization analysis of complex biological mixtures while simultaneously concentrating the analyte into a small volume. Sample incubation and processing methods were such that a typical analysis could be performed in less than 1 h while subnanomolar sensitivities were maintained. The technique has been used for the rapid, selective, and quantitative screening of human blood for the presence of myotoxin a, and Mojave toxin from the venoms of the prairie rattlesnake, Crotalus virdis virdis, and the Mojave rattlesnake, Crotalus scutulatus scutulatus. 18 refs., 8 figs.

  8. Lateral Flow Immunoassay.

    PubMed

    Ching, Kathryn H

    2015-01-01

    Lateral flow immunoassays (LFIAs) are a staple in the field of rapid diagnostics. These small handheld devices require no specialized training or equipment to operate, and generate a result within minutes of sample application. They are an ideal format for many types of home test kits, for emergency responders and for food manufacturers and producers looking for a quick evaluation of a given sample. LFIAs rely on high quality monoclonal antibodies that recognize the analyte of interest. As monoclonal antibody technology becomes more accessible to smaller laboratories, there has been increased interest in developing LFIA prototypes for potential commercial manufacture. In this chapter, the basics of designing and building an LFIA prototype are described. PMID:26160571

  9. Morphological resonances for multicomponent immunoassays

    NASA Astrophysics Data System (ADS)

    Whitten, W. B.; Shapiro, M. J.; Ramsey, J. M.; Bronk, B. V.

    1995-06-01

    An immunoassay technique capable of detecting and identifying a number of species of microorganisms in a single analysis is described. The method uses optical-resonance size discrimination of microspheres to identify antibodies to which stained microorganisms are bound.

  10. Homogeneous enzyme immunoassay for netilmicin.

    PubMed Central

    Wenk, M; Hemmann, R; Follath, F

    1982-01-01

    A newly developed homogeneous enzyme immunoassay for the determination of netilmicin in serum was evaluated and compared with a radioenzymatic assay. A total of 102 serum samples from patients treated with netilmicin were measured by both methods. This comparison showed an excellent correlation (r = 0.993). The enzyme immunoassay has proved to be precise, accurate, and specific. Because of its rapidity and the ease of performance, this method is a useful alternative to current assays for monitoring serum netilmicin concentrations. PMID:6760807

  11. Nanomaterial-based advanced immunoassays.

    PubMed

    Hu, Weihua; Li, Chang Ming

    2011-01-01

    Immunoassay has been the main stream in clinic diagnostics and still attracts extensive research interest in recent years to develop reliable, fast, sensitive, and specific detection methods and platforms to expand its applications in various areas including proteomics, drug discovery, homeland security, food safety, environmental monitoring, and health care. With the dramatic progress in material science, nanotechnology, and bioconjugation techniques, a great diversity of nanomaterials with desirable superior properties have been designed, synthesized, and tailored to facilitate high-performance detections for advanced immunoassays. This paper comprehensively reviews recent advances in nanomaterial-based immunoassay technologies and particularly highlights newly developed strategies associated with interdisciplinary areas for performance enhancement and related mechanisms. The future perspectives of immunosensing technologies are also discussed. PMID:25363746

  12. Fluorescence Immunoassay for Cocaine Detection.

    PubMed

    Nakayama, Hiroshi; Kenjjou, Noriko; Shigetoh, Nobuyuki; Ito, Yuji

    2016-04-01

    A fluorescence immunoassay (FIA) has been developed for the detection of cocaine using norcocaine labeled with merocyanine dye and a monoclonal antibody specific to cocaine. Using this FIA, the detection range for cocaine was between 20.0 and 1700 μg/L with a limit of detection of 20.0 μg/L. Other cocaine derivatives did not interfere significantly with the detection when using this immunoassay technique with cross-reactivity values of less than 20%. Thus this FIA could be considered a useful tool for the detection of cocaine. PMID:26977890

  13. Bioelectrochemical Immunoassay of Polychlorinated Biphenyl

    SciTech Connect

    Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe

    2008-04-01

    A simple, rapid, and highly sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) and disposable screen-printed electrodes (SPE) has been developed to detect polychlorinated biphenyls (PCBs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PCB-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PCB (HRP-PCB). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreactions among PCB-antibody-coated MBs, PCB analyte, and HRP-PCB. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing o-aminophenol and hydrogen peroxide for electrochemical detection. The different parameters, including the amount of HRP-PCB conjugates, immunoreaction time, and the concentration of substrate that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 5 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical immunoassay was successfully evaluated with untreated river water spiked with PCBs, and the results were validated by commercial PCB enzyme-linked immunosorbent assay kit, indicating that this convenient and sensitive technique offers great promise for decentralized environmental application and trace PCBs monitoring.

  14. Protein Adsorption in Microengraving Immunoassays

    PubMed Central

    Song, Qing

    2015-01-01

    Microengraving is a novel immunoassay forcharacterizing multiple protein secretions from single cells. During the immunoassay, characteristic diffusion and kinetic time scales τD and τK determine the time for molecular diffusion of proteins secreted from the activated single lymphocytes and subsequent binding onto the glass slide surface respectively. Our results demonstrate that molecular diffusion plays important roles in the early stage of protein adsorption dynamics which shifts to a kinetic controlled mechanism in the later stage. Similar dynamic pathways are observed for protein adsorption with significantly fast rates and rapid shifts in transport mechanisms when C0* is increased a hundred times from 0.313 to 31.3. Theoretical adsorption isotherms follow the trend of experimentally obtained data. Adsorption isotherms indicate that amount of proteins secreted from individual cells and subsequently captured on a clean glass slide surface increases monotonically with time. Our study directly validates that protein secretion rates can be quantified by the microengraving immunoassay. This will enable us to apply microengraving immunoassays to quantify secretion rates from 104–105 single cells in parallel, screen antigen-specific cells with the highest secretion rate for clonal expansion and quantitatively reveal cellular heterogeneity within a small cell sample. PMID:26501282

  15. Competitive Homogeneous Immunoassay for Rapid Serodiagnosis of Hantavirus Disease

    PubMed Central

    Rusanen, Juuso; Hepojoki, Jussi; Nurmi, Visa; Vaheri, Antti; Lundkvist, Åke; Hedman, Klaus; Vapalahti, Olli

    2015-01-01

    In this study, we describe a competitive homogeneous immunoassay that makes use of Förster resonance energy transfer (FRET) in rapid detection of pathogen-specific antibodies. The assay principle is based on competition between a monoclonal antibody (MAb) and serum antibodies to a given antigen. In the assay, named competitive FRET immunoassay (CFRET-IA), the FRET signal is induced if MAb carrying a donor label binds to an acceptor-labeled antigen. Specific antibodies in serum compete for antigen binding, resulting in reduced FRET signal. The proof-of-principle for the assay was obtained using donor-labeled Puumala virus nucleocapsid protein (PUUV-N) and acceptor-labeled anti-PUUV-N MAb. The assay was evaluated by analyzing 329 clinical samples comprising 101 from individuals with acute PUUV infection, 42 from individuals with past infection, and 186 from individuals with PUUV-seronegative sera, and the results were compared to those of reference tests. The rapid serodiagnostic test we introduced herein performed with 100% sensitivity and 99% specificity for diagnosing acute hantavirus disease. PMID:25972427

  16. IMMUNOASSAYS FOR METAL IONS. (R824029)

    EPA Science Inventory

    Abstract

    Antibodies that recognize chelated forms of metal ions have been used to construct immunoassays for Cd(II), Hg(II), Pb(II), and Ni(II). In this paper, the format of these immunoassays is described and the binding properties of three monoclonal antibodies direc...

  17. Survey of immunoassay techniques for biological analysis

    SciTech Connect

    Burtis, C.A.

    1986-10-01

    Immunoassay is a very specific, sensitive, and widely applicable analytical technique. Recent advances in genetic engineering have led to the development of monoclonal antibodies which further improves the specificity of immunoassays. Originally, radioisotopes were used to label the antigens and antibodies used in immunoassays. However, in the last decade, numerous types of immunoassays have been developed which utilize enzymes and fluorescent dyes as labels. Given the technical, safety, health, and disposal problems associated with using radioisotopes, immunoassays that utilize the enzyme and fluorescent labels are rapidly replacing those using radioisotope labels. These newer techniques are as sensitive, are easily automated, have stable reagents, and do not have a disposal problem. 6 refs., 1 fig., 2 tabs.

  18. Enzyme immunoassays in diagnostic medicine

    PubMed Central

    Voller, A.; Bidwell, D. E.; Bartlett, Ann

    1976-01-01

    Serological methods are playing an increasingly important role in the diagnosis and epidemiological assessment of diseases. Simple, inexpensive methods for large-scale application are urgently needed. The enzyme immunoassay methods developed recently and reviewed here hold great promise for application in a wide variety of conditions. Under laboratory conditions they can be as sensitive as radio-immunoassay, but they can also be adapted as simple field screening procedures. These methods are based on the use of antibodies or antigens that are linked to an insoluble carrier surface. This is then used to “capture” the relevant antigen or antibody in the test solution and the complex is detected by means of an enzyme-labelled antibody or antigen. The degradation of the enzyme substrate, measured photometrically, is proportional to the concentration of the unknown “antibody” or “antigen” in the test solution. The application of these techniques to endocrinology, immunopathology, haematology, microbiology, and parasitology is reviewed. PMID:1085667

  19. Electrokinetic Microstrirring to Enhance Immunoassays

    NASA Astrophysics Data System (ADS)

    Feldman, Hope; Sigurdson, Marin; Meinhart, Carl

    2006-11-01

    Electrokinetic microstirring is used to improve the sensitivity of microfluidic heterogeneous immuno-sensors by enhancing the transport in diffusion-limited reactions. The AC electrokinetic force, Electrothermal Flow, is exploited to create a circular stirring fluid motion, thereby providing more binding opportunities between suspended and wall-immobilized molecules. This process can significantly reduce test times, important for both field-portable biosensors and for lab-based assays. A 2-D numerical simulation model is used to predict the effect of electrothermal flow on a heterogeneous immunoassay resulting from an AC potential applied to two parallel electrodes. The binding is increased by a factor of 7 for an applied voltage of 10 Vrms. The effect was investigated experimentally using a high affinity biotin-streptavidin reaction. Microstirred reaction rates were compared with passive reactions. The measurements show on average an order of magnitude increase in binding between immobilized biotin and fluorescently-labeled streptavidin after 5 minutes. Therefore, this technique shows significant promise for reducing incubation time and enhancing the sensitivity of immunoassays.

  20. Feasibility of a simple microsieve-based immunoassay platform.

    PubMed

    Zweitzig, Daniel R; Tibbe, Arjan G; Nguyen, Ai T; van Rijn, Cees J M; Kopnitsky, Mark J; Cichonski, Kathleen; Terstappen, Leon W M M

    2016-10-01

    The intrinsic properties of silicon microsieves, such as an optically flat surface, high overall porosity, and low flow resistance have led to an increasing number of biotechnology applications. In this report, the feasibility of creating a microsieve-based immunoassay platform was explored. Microsieves containing 5μm pores were coupled with poly-acrylic acid chains, and then mounted into a plastic holder to enable rapid reagent exchanges via a wicking mechanism. The mounted microsieves were coated with infectious disease-related antigens at [2.5 and 25μg/mL], [20 and 50μg/mL], and [20 and 100μg/mL] to facilitate detection of serum-derived human antibodies against Rubella (3-day measles), B. burgdorferi (Lyme disease), or T. pallidum (syphilis), respectively. The prototype microsieve-based immunoassay platform was able to distinguish positive control sera containing antibodies against Rubella, T. pallidum, and B. burgdorferi from negative control sera with similar qualitative results as FDA-approved ELISA tests. Testing of a WHO IgG syphilitic standard at 0.3, 0.15, 0.075, 0.0375, and 0.01875IU/mL demonstrated that the T. pallidum microsieve assay is able to distinguish disease-specific IgG signal from background signal at similar, and possibly lower, levels than the corresponding ELISA. The T. pallidum microsieve assay prototype also differentiated positive clinical serum samples from negative donor samples, and the results were in good agreement with ELISA (R(2)=0.9046). These feasibility studies demonstrate the potential for utilizing microsieves, along with a reagent wicking device, as a simple diagnostic immunoassay platform. PMID:27448458

  1. Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)

    NASA Astrophysics Data System (ADS)

    Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

    2000-03-01

    Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this

  2. Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen.

    PubMed

    Bhuckory, Shashi; Lefebvre, Olivier; Qiu, Xue; Wegner, Karl David; Hildebrandt, Niko

    2016-01-01

    The integration of semiconductor quantum dots (QDs) into homogeneous Förster resonance energy transfer (FRET) immunoassay kits for clinical diagnostics can provide significant advantages concerning multiplexing and sensitivity. Here we present a facile and functional QD-antibody conjugation method using three commercially available QDs with different photoluminescence (PL) maxima (605 nm, 655 nm, and 705 nm). The QD-antibody conjugates were successfully applied for FRET immunoassays against prostate specific antigen (PSA) in 50 µL serum samples using Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated PL detection on a KRYPTOR clinical plate reader. Förster distance and Tb donor background PL were directly related to the analytical sensitivity for PSA, which resulted in the lowest limits of detection for Tb-QD705 (2 nM), followed by Tb-QD655 (4 nM), and Tb-QD605 (23 nM). Duplexed PSA detection using the Tb-QD655 and Tb-QD705 FRET-pairs demonstrated the multiplexing ability of our immunoassays. Our results show that FRET based on QD acceptors is suitable for multiplexed and sensitive biomarker detection in clinical diagnostics. PMID:26861327

  3. Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen

    PubMed Central

    Bhuckory, Shashi; Lefebvre, Olivier; Qiu, Xue; Wegner, Karl David; Hildebrandt, Niko

    2016-01-01

    The integration of semiconductor quantum dots (QDs) into homogeneous Förster resonance energy transfer (FRET) immunoassay kits for clinical diagnostics can provide significant advantages concerning multiplexing and sensitivity. Here we present a facile and functional QD-antibody conjugation method using three commercially available QDs with different photoluminescence (PL) maxima (605 nm, 655 nm, and 705 nm). The QD-antibody conjugates were successfully applied for FRET immunoassays against prostate specific antigen (PSA) in 50 µL serum samples using Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated PL detection on a KRYPTOR clinical plate reader. Förster distance and Tb donor background PL were directly related to the analytical sensitivity for PSA, which resulted in the lowest limits of detection for Tb-QD705 (2 ng/mL), followed by Tb-QD655 (4 ng/mL), and Tb-QD605 (23 ng/mL). Duplexed PSA detection using the Tb-QD655 and Tb-QD705 FRET-pairs demonstrated the multiplexing ability of our immunoassays. Our results show that FRET based on QD acceptors is suitable for multiplexed and sensitive biomarker detection in clinical diagnostics. PMID:26861327

  4. [FT4 immunoassay interference : A case report].

    PubMed

    Chaabouni, Khansa; Hargafi, Khaoula; Elleuch, Aida; Messedi, Mariem; Turki, Mouna; Lahyani, Amina; Ayedi, Fatma

    2015-04-01

    Measurement of thyrotropin and free thyroxin made using immunoassays are usually needed in clinical endocrinology. Here, we report a case of a patient with type 2 diabetes who presented a weight loss. To eliminate hyperthyroidism, thyroid function tests were performed. Free thyroxin (FT4) was decreased using two automated immunoassays TOSOH AIA 1800 and Roche ELECSYS 2010, with a normal thyrotropin value. Thyroid function tests repeated a month later were normal. The patient's history revealed contact with sheep, which may partly explain the interference. Investigations into the patient's serum were carried out using both the PEG test and dilution test. Interference factors were probably antibodies. Despite progress in immunoassays, we should be aware of interference occurrence since it can lead to false results, unnecessary investigations and incorrect treatment. Thus, simple tests must be carried out as if interference in immunoassays were suspected. Dilutions and PEG tests are generally performed as first line investigations. PMID:26375746

  5. Colorimetric Immunoassay for Detection of Tumor Markers

    PubMed Central

    Yin, Yongmei; Cao, Ya; Xu, Yuanyuan; Li, Genxi

    2010-01-01

    Tumor markers are substances, usually proteins, produced by the body in response to cancer growth, or by the cancer tissue itself. They can be detected in blood, urine, or tissue samples, and the discovery and detection of tumor markers may provide earlier diagnosis of cancer and improved therapeutic intervention. Colorimetric immunoassays for tumor marker detection have attracted considerable attention, due to their simplicity and high efficiency. The traditionally used colorimetric immunoassays for the detection of tumor markers are based on enzyme-linked immunosorbent assays, and the great achievement of nanotechnology has further opened opportunities for the development of such kind of immunoassays. This paper will summarize recent advances in the field of colorimetric immunoassays for detecting tumor markers, which is aimed to provide an overview in this field, as well as experimental guidance for the learner. PMID:21614193

  6. Fluorescent excitation transfer immunoassay for the determination of spinosyn A in water.

    PubMed

    Lee, M; Walt, D R; Nugent, P

    1999-07-01

    A fluorescent excitation transfer immunoassay for spinosyn A, a fermentation derived insect control agent, has been developed and applied to the analysis of tap water and wastewater effluent from manufacturing plants. Fluorescein (F) and tetramethylrhodamine (TMR) were chosen as donor and quencher, respectively, for the excitation transfer. Fluorescence quenching was observed from the binding of F-labeled antigen to TMR-labeled antibody. By employing nonlabeled antigen in a competitive immunoassay format, we reversed fluorescence quenching. The assay provides a limit of detection of 0. 01 ppb and a working range of 0.05-1 ppb and allows for the rapid determination of spinosyn A in water with recovery values ranging from 96% to 120%. With the exploitation of the small size of optical fibers, fluorescence from an assay volume of 24 microL could be measured without special vessels. PMID:10552562

  7. Automated immunoassays for 25-hydroxyvitamin D (25-OHD): do plasticisers interfere?

    PubMed

    Carter, G D; Jones, J; Ketheeswaran, M; Shannon, J; Singh, B; Kearney, E; Berry, J L

    2015-04-01

    The international quality assessment scheme for vitamin D metabolites (DEQAS) was established in 1989. The scheme involves the quarterly distribution of 5 serum samples prepared from blood collected in plain plastic bags. Following transfer of the donors to a clinic using different bags, sera were found to contain a contaminant that interfered in both the local LC-MS/MS assay and the NIST reference measurement procedure for 25-OHD. It seemed likely that the contaminant was a substance, possibly a plasticiser, leached from the plastic bag. It was subsequently suggested that the unidentified contaminant might also cause interference in certain automated non-extraction assays for 25-OHD. This was investigated in 3 automated immunoassays by comparing serum 25-OHD results from blood collected simultaneously into plain glass tubes and plastic bags. There was no significant difference in results, indicating that the leached substance had no effect on any of the 3 immunoassays examined. PMID:25448742

  8. Immunoassays in monitoring biotechnological drugs.

    PubMed

    Gygax, D; Botta, L; Ehrat, M; Graf, P; Lefèvre, G; Oroszlan, P; Pfister, C

    1996-08-01

    For the evaluation and interpretation of pharmacokinetic data reliable quantitative determinations are a requirement that can only be met by well-characterized and fully validated analytical methods. To cope with these requirements a method is being established that is based on an integrated and automated fiber-optic biospecific interaction analysis system (FOBIA) for immunoassays. Performance characteristics of this system used in monitoring of recombinant hirudin (CGP 39 393) are presented. Recombinant hirudin is a highly potent and selective inhibitor of human thrombin. Owing to its size and charge, recombinant hirudin is mainly eliminated by glomerular filtration. But only a fraction of the hirudin dose seems to be reabsorbed at the proximal tubule by luminal endocytosis and hydrolyzed by lysosomal enzymes, leaving approximately 50% of the dose to be extracted in the urine. Thus, renal clearance of recombinant hirudin in the absence of renal insufficiency appears to depend primarily on the glomerular filtration rate. During a 3-month i.v. tolerability study in dogs, some of the dogs developed antibodies against recombinant hirudin. The hirudin-antibody complex accumulated in plasma and apparent hirudin plasma concentrations were therefore much higher than expected from single-dose kinetics. Hirudin captured by antibodies showed an extended half-life and the hirudin-antibody complex is still pharmacologically active, as demonstrated by the observed increase in thrombin time. In conclusion, only appropriate analytical methods allow adequate monitoring and pharmacokinetic characterization of biotechnology drugs in biological materials. PMID:8857560

  9. Human T-cell lymphotropic virus in volunteer blood donors.

    PubMed

    Taylor, P E; Stevens, C E; Pindyck, J; Schrode, J; Steaffens, J W; Lee, H

    1990-01-01

    Serum samples collected in 1985 and 1986 from 18,257 donors to the Greater New York Blood Program were screened by enzyme-linked immunoassay for antibody to human T-cell lymphotropic virus (anti-HTLV). Fifteen samples (0.08%) were confirmed positive: 7 by radioimmunoprecipitation assay (RIPA) alone, 6 by Western blot alone, and 2 by combined results from both tests. One donor, whose original test result was uninterpretable because multiple nonspecific bands were present on RIPA, clearly tested positive on subsequent specimens. Follow-up testing of individuals with this type of result may be needed to resolve their HTLV status. Anti-HTLV prevalence increased with age and was significantly more common in black or Hispanic donors and in those born in the Caribbean than in other donors. All anti-HTLV-positive donors were negative for antibody to HIV-1, and only one donor (7% of those positive) would have been excluded by any of the routine donor screening tests used at that time. PMID:2173176

  10. Donor Tag Game

    MedlinePlus

    ... Cross chapter closest to you. Can't Donate Blood? A financial donation can also help save lives. Donate Now Find ... Donation Student Donors Donation Process Eligibility Blood FAQs Blood Donor Community Learn About Blood Blood Facts and Statistics ...

  11. Becoming a Donor

    MedlinePlus

    ... by Organ and Gender. > U.S. Waiting List Candidate Data HOW TO BECOME A DONOR The most important thing to do is to sign up as an organ and tissue donor in your state's donor registry. To cover all bases, it's also helpful to: Designate your decision on ...

  12. Donor corneal tissue evaluation.

    PubMed

    Saini, J S; Reddy, M K; Sharma, S; Wagh, S

    1996-03-01

    Proper evaluation of donor cornea is critical to the success of corneal transplantation. Attention must be paid to the cause of death and ocular condition as several general and ocular diseases constitute contraindications for donor corneal usage. Death to enucleation time should be noted. Gross examination and slit lamp biomicroscopy are mandatory for the evaluation of the donor eye while specular microscopy adds another useful dimension to information regarding donor cornea. This article provides a comprehensive review of all the aspects of donor corneal evaluation as practised today worldwide. PMID:8828299

  13. Ca2+-Regulated Photoproteins: Effective Immunoassay Reporters

    PubMed Central

    Frank, Ludmila A.

    2010-01-01

    Ca2+-regulated photoproteins of luminous marine coelenterates are of interest and a challenge for researchers as a unique bioluminescent system and as a promising analytical instrument for both in vivo and in vitro applications. The proteins are comprehensively studied as to biochemical properties, tertiary structures, bioluminescence mechanism, etc. This knowledge, along with available recombinant proteins serves the basis for development of unique bioluminescent detection systems that are “self-contained”, triggerable, fast, highly sensitive, and non-hazardous. In the paper, we focus on the use of photoproteins as reporters in binding assays based on immunological recognition element—bioluminescent immunoassay and hybridization immunoassay, their advantages and prospects. PMID:22163526

  14. Laparoscopic live donor nephrectomy.

    PubMed

    Hasan, Waleed A; Al-Akraa, Mahmoud M

    2005-07-01

    With the number of patients presently awaiting renal transplantation exceeding the number of cadaveric organs available, there is an increasing reliance on live renal donation. Of the 11,869 renal transplants performed in 2002 in the US, 52.6% were living donors from the United Network for Organ Sharing Registry. Renal allografts from living donors provide: superior immediate long-term function; require less waiting time and are more cost-effective than those from cadaveric donors. However, anticipation of postoperative pain and temporary occupational disability may dissuade many potential donors. Additionally, some recipients hesitate to accept a living donor kidney due to suffering that would be endured by the donor. It is a unique medical situation when a young, completely healthy donor undergoes a major surgical procedure to provide an organ for transplantation. It is mandatory to offer a surgical technique, which is safe and with minimal complications. It is also obvious for any organ transplantation, that the integrity of the organ remain intact, thus, enabling its successful transplantation into the recipient. An acceptably short ischemia time and adequate lengths of ureter and renal vasculature are favored. Many centers are performing laparoscopic live donor nephrectomy in an effort to ease convalescence of renal donors. This may encourage the consideration of live donation by recipients and potential donors. PMID:16047050

  15. Lung donor selection criteria

    PubMed Central

    Chaney, John; Suzuki, Yoshikazu; Cantu, Edward

    2014-01-01

    The criteria that define acceptable physiologic and social parameters for lung donation have remained constant since their empiric determination in the 1980s. These criteria include a donor age between 25-40, a arterial partial pressure of oxygen (PaO2)/FiO2 ratio greater than 350, no smoking history, a clear chest X-ray, clean bronchoscopy, and a minimal ischemic time. Due to the paucity of organ donors, and the increasing number of patients requiring lung transplant, finding a donor that meets all of these criteria is quite rare. As such, many transplants have been performed where the donor does not meet these stringent criteria. Over the last decade, numerous reports have been published examining the effects of individual acceptance criteria on lung transplant survival and graft function. These studies suggest that there is little impact of the historical criteria on either short or long term outcomes. For age, donors should be within 18 to 64 years old. Gender may relay benefit to all female recipients especially in male to female transplants, although results are mixed in these studies. Race matched donor/recipients have improved outcomes and African American donors convey worse prognosis. Smoking donors may decrease recipient survival post transplant, but provide a life saving opportunity for recipients that may otherwise remain on the transplant waiting list. No specific gram stain or bronchoscopic findings are reflected in recipient outcomes. Chest radiographs are a poor indicator of lung donor function and should not adversely affect organ usage aside for concerns over malignancy. Ischemic time greater than six hours has no documented adverse effects on recipient mortality and should not limit donor retrieval distances. Brain dead donors and deceased donors have equivalent prognosis. Initial PaO2/FiO2 ratios less than 300 should not dissuade donor organ usage, although recruitment techniques should be implemented with intent to transplant. PMID:25132970

  16. Lung donor selection criteria.

    PubMed

    Chaney, John; Suzuki, Yoshikazu; Cantu, Edward; van Berkel, Victor

    2014-08-01

    The criteria that define acceptable physiologic and social parameters for lung donation have remained constant since their empiric determination in the 1980s. These criteria include a donor age between 25-40, a arterial partial pressure of oxygen (PaO2)/FiO2 ratio greater than 350, no smoking history, a clear chest X-ray, clean bronchoscopy, and a minimal ischemic time. Due to the paucity of organ donors, and the increasing number of patients requiring lung transplant, finding a donor that meets all of these criteria is quite rare. As such, many transplants have been performed where the donor does not meet these stringent criteria. Over the last decade, numerous reports have been published examining the effects of individual acceptance criteria on lung transplant survival and graft function. These studies suggest that there is little impact of the historical criteria on either short or long term outcomes. For age, donors should be within 18 to 64 years old. Gender may relay benefit to all female recipients especially in male to female transplants, although results are mixed in these studies. Race matched donor/recipients have improved outcomes and African American donors convey worse prognosis. Smoking donors may decrease recipient survival post transplant, but provide a life saving opportunity for recipients that may otherwise remain on the transplant waiting list. No specific gram stain or bronchoscopic findings are reflected in recipient outcomes. Chest radiographs are a poor indicator of lung donor function and should not adversely affect organ usage aside for concerns over malignancy. Ischemic time greater than six hours has no documented adverse effects on recipient mortality and should not limit donor retrieval distances. Brain dead donors and deceased donors have equivalent prognosis. Initial PaO2/FiO2 ratios less than 300 should not dissuade donor organ usage, although recruitment techniques should be implemented with intent to transplant. PMID:25132970

  17. A photoacoustic immunoassay for biomarker detection.

    PubMed

    Zhao, Yunfei; Cao, Mingfeng; McClelland, John F; Shao, Zengyi; Lu, Meng

    2016-11-15

    Challenges in protein biomarker analysis include insufficient sensitivity for detecting low-abundance biomarkers, poor measurement reproducibility, and the high costs and large footprints of detection systems. To address these issues, a new detection modality was developed for analyzing protein biomarkers based on the plasmon-enhanced photoacoustic (PA) effect. The detection modality employed a heterogeneous immunoassay scheme and used gold nanoparticles (AuNPs) as the signal reporter. Due to their localized plasmon resonance, AuNPs can strongly interact with intensity-modulated laser excitation and generate strong PA signals, which are subsequently sensed and quantified using a microphone. As an example, the performance of the PA immunoassay was evaluated by detecting the human interleukin 8 chemokine. The PA immunoassay provided approximately 143× lower limit of detection (LOD) than observed with the gold standard enzyme-linked immunosorbent assay - a decrease from 23pg/mL to 0.16pg/mL. In addition to the significant performance improvement in terms of the LOD, the PA immunoassay also offers advantages in terms of compatibility with low-cost instruments and the long-term stability of assay results. PMID:27183276

  18. Homogeneous model immunoassay of thyroxine by phase-modulation fluorescense spectroscopy

    NASA Astrophysics Data System (ADS)

    Ozinskas, Alvydas J.; Malak, Henryk M.; Britz, Judy; Thompson, Richard B.; Koen, Peter A.; Lakowicz, Joseph R.

    1993-05-01

    We describe a homogeneous competitive model immunoassay for determination of thyroxine by multi-frequency phase-modulation fluorescence. Using a non-radiative energy transfer transduction mechanism, B-phycoerythrin conjugated to thyroxine is the energy donor and a carboxymethylindocyanine dye conjugated to anti-thyroxine antibody is the energy acceptor. Energy transfer from B-phycoerythrin to the acceptor results in a decreased lifetime and/or phase angle. The fluorescence lifetime change reflects the extent of energy transfer. In the competitive immunoassay format, the donor-thyroxine conjugate and an analytical sample of thyroxine compete for acceptor-antibody binding sites, resulting in a phase angle change which is dependent on the amount of thyroxine in the sample. Dose response curves of phase angle versus thyroxine concentration demonstrate a broader dynamic range than comparable steady state intensity curves. Since phase-modulation lifetime measurements are largely independent of total signal intensity, sources of optical interference are minimized. The potential for whole blood measurements exists since the energy transfer lifetime method can be extended to longer wavelengths.

  19. Highly Sensitive Homogeneous Immunoassays Based on Construction of Silver Triangular Nanoplates-Quantum Dots FRET System

    PubMed Central

    Zeng, Qinghui; Li, Qin; Ji, Wenyu; Bin, Xue; Song, Jie

    2016-01-01

    With growing concerns about health issues worldwide, elegant sensors with high sensitivity and specificity for virus/antigens (Ag) detection are urgent to be developed. Homogeneous immunoassays (HIA) are an important technique with the advantages of small sample volumes requirement and pretreatment-free process. HIA are becoming more favorable for the medical diagnosis and disease surveillance than heterogeneous immunoassays. An important subset of HIA relies on the effect of fluorescence resonance energy transfer (FRET) via a donor-acceptor (D–A) platform, e.g., quantum dots (QDs) donor based FRET system. Being an excellent plasmonic material, silver triangular nanoplates (STNPs) have unique advantages in displaying surface plasmon resonance in the visible to near infrared spectral region, which make them a better acceptor for pairing with QDs in a FRET-based sensing system. However, the reported STNPs generally exhibited broad size distributions, which would greatly restrict their application as HIA acceptor for high detection sensitivity and specificity purpose. In this work, uniform STNPs and red-emitting QDs are firstly applied to construct FRET nanoplatform in the advanced HIA and further be exploited for analyzing virus Ag. The uniform STNPs/QDs nanoplatform based medical sensor provides a straightforward and highly sensitive method for Ag analysis in homogeneous form. PMID:27198713

  20. Highly Sensitive Homogeneous Immunoassays Based on Construction of Silver Triangular Nanoplates-Quantum Dots FRET System

    NASA Astrophysics Data System (ADS)

    Zeng, Qinghui; Li, Qin; Ji, Wenyu; Bin, Xue; Song, Jie

    2016-05-01

    With growing concerns about health issues worldwide, elegant sensors with high sensitivity and specificity for virus/antigens (Ag) detection are urgent to be developed. Homogeneous immunoassays (HIA) are an important technique with the advantages of small sample volumes requirement and pretreatment-free process. HIA are becoming more favorable for the medical diagnosis and disease surveillance than heterogeneous immunoassays. An important subset of HIA relies on the effect of fluorescence resonance energy transfer (FRET) via a donor-acceptor (D–A) platform, e.g., quantum dots (QDs) donor based FRET system. Being an excellent plasmonic material, silver triangular nanoplates (STNPs) have unique advantages in displaying surface plasmon resonance in the visible to near infrared spectral region, which make them a better acceptor for pairing with QDs in a FRET-based sensing system. However, the reported STNPs generally exhibited broad size distributions, which would greatly restrict their application as HIA acceptor for high detection sensitivity and specificity purpose. In this work, uniform STNPs and red-emitting QDs are firstly applied to construct FRET nanoplatform in the advanced HIA and further be exploited for analyzing virus Ag. The uniform STNPs/QDs nanoplatform based medical sensor provides a straightforward and highly sensitive method for Ag analysis in homogeneous form.

  1. Highly Sensitive Homogeneous Immunoassays Based on Construction of Silver Triangular Nanoplates-Quantum Dots FRET System.

    PubMed

    Zeng, Qinghui; Li, Qin; Ji, Wenyu; Bin, Xue; Song, Jie

    2016-01-01

    With growing concerns about health issues worldwide, elegant sensors with high sensitivity and specificity for virus/antigens (Ag) detection are urgent to be developed. Homogeneous immunoassays (HIA) are an important technique with the advantages of small sample volumes requirement and pretreatment-free process. HIA are becoming more favorable for the medical diagnosis and disease surveillance than heterogeneous immunoassays. An important subset of HIA relies on the effect of fluorescence resonance energy transfer (FRET) via a donor-acceptor (D-A) platform, e.g., quantum dots (QDs) donor based FRET system. Being an excellent plasmonic material, silver triangular nanoplates (STNPs) have unique advantages in displaying surface plasmon resonance in the visible to near infrared spectral region, which make them a better acceptor for pairing with QDs in a FRET-based sensing system. However, the reported STNPs generally exhibited broad size distributions, which would greatly restrict their application as HIA acceptor for high detection sensitivity and specificity purpose. In this work, uniform STNPs and red-emitting QDs are firstly applied to construct FRET nanoplatform in the advanced HIA and further be exploited for analyzing virus Ag. The uniform STNPs/QDs nanoplatform based medical sensor provides a straightforward and highly sensitive method for Ag analysis in homogeneous form. PMID:27198713

  2. FRET-Based Quantum Dot Immunoassay for Rapid and Sensitive Detection of Aspergillus amstelodami

    PubMed Central

    Kattke, Michele D.; Gao, Elizabeth J.; Sapsford, Kim E.; Stephenson, Larry D.; Kumar, Ashok

    2011-01-01

    In this study, a fluorescence resonance energy transfer (FRET)-based quantum dot (QD) immunoassay for detection and identification of Aspergillus amstelodami was developed. Biosensors were formed by conjugating QDs to IgG antibodies and incubating with quencher-labeled analytes; QD energy was transferred to the quencher species through FRET, resulting in diminished fluorescence from the QD donor. During a detection event, quencher-labeled analytes are displaced by higher affinity target analytes, creating a detectable fluorescence signal increase from the QD donor. Conjugation and the resulting antibody:QD ratios were characterized with UV-Vis spectroscopy and QuantiT protein assay. The sensitivity of initial fluorescence experiments was compromised by inherent autofluorescence of mold spores, which produced low signal-to-noise and inconsistent readings. Therefore, excitation wavelength, QD, and quencher were adjusted to provide optimal signal-to-noise over spore background. Affinities of anti-Aspergillus antibody for different mold species were estimated with sandwich immunoassays, which identified A. fumigatus and A. amstelodami for use as quencher-labeled- and target-analytes, respectively. The optimized displacement immunoassay detected A. amstelodami concentrations as low as 103 spores/mL in five minutes or less. Additionally, baseline fluorescence was produced in the presence of 105 CFU/mL heat-killed E. coli O157:H7, demonstrating high specificity. This sensing modality may be useful for identification and detection of other biological threat agents, pending identification of suitable antibodies. Overall, these FRET-based QD-antibody biosensors represent a significant advancement in detection capabilities, offering sensitive and reliable detection of targets with applications in areas from biological terrorism defense to clinical analysis. PMID:22163961

  3. Rational design of a low-affinity peptide for the detection of cystatin C in a fast homogeneous immunoassay.

    PubMed

    Dobslaff, Kristin; Zscharnack, Kristin; Kreisig, Thomas; Zuchner, Thole

    2016-02-01

    Immunoassays play an essential role in current research and diagnostics resulting in a variety of detection principles. Thereby, homogeneous assays are often used for a fast signal response as demanded for example in point-of-care diagnostics. These systems often rely on a competitive assay design where the sample analyte and the corresponding dye-labeled substance are competing for binding sites on an antibody present in limited amounts. Due to the similar affinities of the antibody towards the sample analyte and the competitor, both sensitivity and assay time are limited. As a consequence, a competitor with a slightly reduced affinity towards the antibody can potentially overcome these drawbacks. Here, we present the rational design of a low-affinity peptide (donor peptide) as a specific analyte competitor for a FRET-based homogeneous immunoassay for the analysis of the protein cystatin C. Thereby, the strategy of peptide-induced antibody generation was combined with the selective variation of the immunization sequence in order to achieve a lower affinity towards the antibody. We could show that shortened donor peptides improved the resulting quenching efficiency in the immunoassay. In addition, the substitution of small hydrophobic amino acids by those with a higher steric demand appeared to be the most promising strategy providing a fast assay response for cystatin C of only 90 s. PMID:26403846

  4. Theoretical limitations of quantification for noncompetitive sandwich immunoassays.

    PubMed

    Woolley, Christine F; Hayes, Mark A; Mahanti, Prasun; Douglass Gilman, S; Taylor, Tom

    2015-11-01

    Immunoassays exploit the highly selective interaction between antibodies and antigens to provide a vital method for biomolecule detection at low concentrations. Developers and practitioners of immunoassays have long known that non-specific binding often restricts immunoassay limits of quantification (LOQs). Aside from non-specific binding, most efforts by analytical chemists to reduce the LOQ for these techniques have focused on improving the signal amplification methods and minimizing the limitations of the detection system. However, with detection technology now capable of sensing single-fluorescence molecules, this approach is unlikely to lead to dramatic improvements in the future. Here, fundamental interactions based on the law of mass action are analytically connected to signal generation, replacing the four- and five-parameter fittings commercially used to approximate sigmoidal immunoassay curves and allowing quantitative consideration of non-specific binding and statistical limitations in order to understand the ultimate detection capabilities of immunoassays. The restrictions imposed on limits of quantification by instrumental noise, non-specific binding, and counting statistics are discussed based on equilibrium relations for a sandwich immunoassay. Understanding the maximal capabilities of immunoassays for each of these regimes can greatly assist in the development and evaluation of immunoassay platforms. While many studies suggest that single molecule detection is possible through immunoassay techniques, here, it is demonstrated that the fundamental limit of quantification (precision of 10 % or better) for an immunoassay is approximately 131 molecules and this limit is based on fundamental and unavoidable statistical limitations. PMID:26342315

  5. Rich Donors, Poor Countries

    ERIC Educational Resources Information Center

    Thomas, M. A.

    2012-01-01

    The shifting ideological winds of foreign aid donors have driven their policy towards governments in poor countries. Donors supported state-led development policies in poor countries from the 1940s to the 1970s; market and private-sector driven reforms during the 1980s and 1990s; and returned their attention to the state with an emphasis on…

  6. Donor Telomere Length SAA

    Cancer.gov

    A new NCI study has found that, among patients with severe aplastic anemia who received a hematopoietic cell transplant from an unrelated donor, those whose donor white blood cells had longer telomeres had higher survival rates five-years after transplant

  7. Donor selection and management.

    PubMed

    Snell, Gregory I; Paraskeva, Miranda; Westall, Glen P

    2013-06-01

    This article reviews recent developments in the selection, assessment, and management of the potential lung donor, which aim to increase donor organ use. The scarcity of suitable donor organs continues to limit lung transplantation, but the situation is changing. An expanded donor pool, including the now widespread use of donation after cardiac death (DCD) lungs; the use of extended donor lungs; and the ability of ex vivo lung perfusion (EVLP) to evaluate and improve donor lungs are key initiatives. These strategies have substantially lifted donor lung utilization rates from historically low levels of less than 15% to rates greater than 50%. Indeed, since 2004 there has been an accelerated year-on-year increase in the number of lungs transplanted globally. Intermediate-term studies are now confirming that long-term outcomes are not being significantly compromised and that more individuals with terminal, symptomatic lung disease are being transplanted. It is now quite clear that many of the historical factors used to define a lung as "extended" do not actually produce significantly inferior outcomes. There has been a dramatic increase in research and clinical interest in donor lung assessment, management, and novel therapeutic strategies. The lessons learned are now being applied widely beyond the lung as researchers aim to increase availability and optimize other solid organs for transplantation. PMID:23821510

  8. Multiplexed Microsphere Suspension Array-Based Immunoassays.

    PubMed

    Lin, Andrew; Salvador, Alexandra; Carter, J Mark

    2015-01-01

    ELISA is an extremely powerful tool to detect analytes because of its sensitivity, selectivity, reproducibility and ease of use. Here we describe sandwich immunoassays performed in suspension on spectrally unique microspheres developed by Luminex. Luminex assays offer the benefit of multiplex analysis of large numbers of analytes in a single reaction. Because the microspheres are spectrally unique, many microspheres, each attached to various antibodies, can be added to a single sample. Luminex instruments can distinguish each microsphere and detect the intensity of a reporter signal for each microsphere. Results are reported in Median Fluorescent Intensities for each analyte. Luminex assays can be used to detect up to 500 analytes in a high-throughput format. Luminex refers to this technology as xMAP(®). Here we describe a routine protocol for a Luminex immunoassay. Other Luminex assays would have to be optimized for specific conditions according to their use. PMID:26160569

  9. Screening and diagnostic performance of enzyme immunoassay for antibody to lymphadenopathy-associated virus.

    PubMed Central

    Handsfield, H H; Wandell, M; Goldstein, L; Shriver, K

    1987-01-01

    In a multicenter cooperative study, an enzyme immunoassay (EIA) using purified antigen of lymphadenopathy-associated virus was compared with radioimmune precipitation (RIP) for detection of antibody to human immunodeficiency virus (HIV) in 634 patients with acquired immunodeficiency syndrome or related conditions, 687 apparently healthy persons at risk for HIV infection, 93 controls with cancer or autoimmune diseases, and 10,038 blood or plasma donors. Excluding the donors, the EIA was reactive in 875 (61.9%) of 1,414 subjects; compared with RIP, the sensitivity and specificity of EIA both were 99.8%. There was one false-positive EIA among 148 intravenous drug abusers and two false-negative EIAs among 472 apparently healthy homosexual men; no other discordant results between EIA and RIP occurred in these subjects. The EIA was repeatably reactive in 20 donors (0.2%), among whom 13 (65%) were positive by RIP; none of 529 randomly selected EIA-negative donors was RIP positive. In addition to its utility as a screening test in low-risk populations, the EIA for antibody to lymphadenopathy-associated virus is useful as a diagnostic test in persons with clinical evidence of or at risk for HIV infection. Images PMID:3294890

  10. Homogeneous Immunoassays: Historical Perspective and Future Promise

    NASA Astrophysics Data System (ADS)

    Ullman, Edwin F.

    1999-06-01

    The founding and growth of Syva Company is examined in the context of its leadership role in the development of homogeneous immunoassays. The simple mix and read protocols of these methods offer advantages in routine analytical and clinical applications. Early homogeneous methods were based on insensitive detection of immunoprecipitation during antigen/antibody binding. The advent of reporter groups in biology provided a means of quantitating immunochemical binding by labeling antibody or antigen and physically separating label incorporated into immune complexes from free label. Although high sensitivity was achieved, quantitative separations were experimentally demanding. Only when it became apparent that reporter groups could provide information, not only about the location of a molecule but also about its microscopic environment, was it possible to design practical non-separation methods. The evolution of early homogenous immunoassays was driven largely by the development of improved detection strategies. The first commercial spin immunoassays, developed by Syva for drug abuse testing during the Vietnam war, were followed by increasingly powerful methods such as immunochemical modulation of enzyme activity, fluorescence, and photo-induced chemiluminescence. Homogeneous methods that quantify analytes at femtomolar concentrations within a few minutes now offer important new opportunities in clinical diagnostics, nucleic acid detection and drug discovery.

  11. Sequential injection immunoassay for environmental measurements.

    PubMed

    Soh, Nobuaki; Tanaka, Mayumi; Hirakawa, Koji; Zhang, RuiQi; Nakajima, Hizuru; Nakano, Koji; Imato, Toshihiko

    2011-01-01

    Sequential injection immunoassay systems for environmental measurements based on the selective immunoreaction between antigen and antibody were described. A sequential injection analysis (SIA) technique is suitable to be applied for the procedure of enzyme-linked immunosorbent assay (ELISA), because the washing and the addition of reagent solutions can be automated by using a computer-controlled syringe pump and switching valve. We selected vitellogenin (Vg), which is a biomarker for evaluating environmental risk caused by endocrine-disrupting chemicals in the hydrosphere, and linear alkylbenzene sulfonates (LAS) and alkylphenol polyethoxylates (APEO), which are versatile surfactants, as target analytes in the flow immunoassay systems. For Vg monitoring, SIA systems based on spectrophotometric, chemiluminescence, and electrochemical determinations were constructed. On the other hand, chemiluminescence determination was applied to the detection of LAS and APEO. For APEO, an SIA system combined with surface plasmon resonance (SPR) sensor was also developed. These new sequential injection immunoassay systems are expected to be useful systems for environmental analysis. PMID:22076332

  12. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays.

    PubMed

    Chen, Hui; Hagström, Anna E V; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C; Atmar, Robert L; Willson, Richard C

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  13. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays

    PubMed Central

    Chen, Hui; Hagström, Anna E. V.; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C.; Atmar, Robert L.; Willson, Richard C.

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 106 virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  14. Antinuclear antibody detection by automated multiplex immunoassay in untreated patients at the time of diagnosis.

    PubMed

    Op De Beéck, Katrijn; Vermeersch, Pieter; Verschueren, Patrick; Westhovens, René; Mariën, Godelieve; Blockmans, Daniel; Bossuyt, Xavier

    2012-12-01

    Fully automated multiplex immunoassays are increasingly used as first line screening for antinuclear antibodies. The diagnostic performance of such multiplex assays in untreated patients at the time of diagnosis has not been reported. Antinuclear antibodies were measured by indirect immunofluorescence (IIF) (dilution 1:160) and by BioPlex 2200 ANA screen (antibodies to dsDNA, chromatin, ribosomal protein, SSA-52, SSA-60, SSB, Sm, SmRNP, RNP-A, RNP-68, Scl-70, Jo-1, and centromere B) in 236 patients with a systemic rheumatic disease at the time of diagnosis, 149 blood donors, 139 patients with chronic fatigue syndrome (CFS), and 134 diseased controls. BioPlex ANA screen and IIF were positive in, respectively, 79% and 90% of patients with systemic lupus erythematosus (SLE), 60% and 60% with cutaneous lupus, 72% and 93% with systemic sclerosis (SSc), 100% and 100% with mixed connective tissue disease (MCTD), 89% and 56% with primary Sjögren's (SS) syndrome, 36% and 36% with polymyositis/dermatomyositis, 5.4% and 6% of blood donors, 7.2% and 3.6% of patients with CFS, and 11% and 18% of diseased controls. BioPlex test result interval specific likelihood ratios increased with increasing antibody concentration. The simultaneous presence of at least three antibodies by BioPlex was found in 35% of patients with SLE, 4% with SSc, 100% with MCTD, 64% with SS, 7% with inflammatory myopathy, 0.7% of CFS and diseased controls, and none of the blood donors. In conclusion, test result specific likelihood ratios and the presence of multiple autoantibodies help with the interpretation of data generated by multiplex immunoassays. PMID:22387973

  15. Living Donor Liver Transplantation

    MedlinePlus

    ... around the scar. The bulges can usually be fixed with surgery. During your medical exam, ask the ... to find out if the donor's blood type matches the recipient’s blood type. Next, the transplant team ...

  16. Laparoscopic donor nephrectomy.

    PubMed

    Deger, S; Giessing, M; Roigas, J; Wille, A H; Lein, M; Schönberger, B; Loening, S A

    2005-01-01

    Laparoscopic live donor nephrectomy (LDN) has removed disincentives of potential donors and may bear the potential to increase kidney donation. Multiple modifications have been made to abbreviate the learning curve while at the same time guarantee the highest possible level of medical quality for donor and recipient. We reviewed the literature for the evolution of the different LDN techniques and their impact on donor, graft and operating surgeon, including the subtleties of different surgical accesses, vessel handling and organ extraction. We performed a literature search (PubMed, DIMDI, medline) to evaluate the development of the LDN techniques from 1995 to 2003. Today more than 200 centres worldwide perform LDN. Hand-assistance has led to a spread of LDN. Studies comparing open and hand-assisted LDN show a reduction of operating and warm ischaemia times for the hand-assisted LDN. Different surgical access sites (trans- or retroperitoneal), different vessel dissection approaches, donor organ delivery techniques, delivery sites and variations of hand-assistance techniques reflect the evolution of LDN. Proper techniques and their combination for the consecutive surgical steps minimize both warm ischaemia time and operating time while offering the donor a safe minimally invasive laparoscopic procedure. LDN has breathed new life into the moribund field of living kidney donation. Within a few years LDN could become the standard approach in living kidney donation. Surgeons working in this field must be trained thoroughly and well acquainted with the subtleties of the different LDN techniques and their respective advantages and disadvantages. PMID:16754618

  17. Live-donor nephrectomy.

    PubMed

    Rocca, Juan P; Davis, Eric; Edye, Michael

    2012-01-01

    Six decades after its first implementation, kidney transplantation remains the optimal therapy for end-stage renal disease requiring dialysis. Despite the incontrovertible mortality reduction and cost-effectiveness of kidney transplantation, the greatest remaining barrier to treatment of end-stage renal disease is organ availability. Although the waiting list of patients who stand to benefit from kidney transplantation grows at a rate proportional to the overall population and proliferation of diabetes and hypertension, the pool of deceased-donor organs available for transplantation experiences minimal to no growth. Because the kidney is uniquely suited as a paired organ, the transplant community's answer to this shortage is living donation of a healthy volunteer's kidney to a recipient with end-stage renal disease. This review details the history and evolution of living-donor kidney transplantation in the United States as well as advances the next decade promises. Laparoscopic donor nephrectomy has overcome many of the obstacles to living donation in terms of donor morbidity and volunteerism. Known donor risks in terms of surgical and medical morbidity are reviewed, as well as the ongoing efforts to delineate and mitigate donor risk in the context of accumulating recipient morbidity while on the waiting list. PMID:22678857

  18. Development of SERS substrates for immunoassay applications

    NASA Astrophysics Data System (ADS)

    Celik, Okkes; Kahraman, Mehmet

    2016-03-01

    Surface-enhanced Raman scattering (SERS) is an emerging technique for the detection and identification of biological structures. SERS is based on immunoassay methods are mostly used for the specific detection and identification of bacteria. In this study, SERS substrates are developed with deposition of synthesized spherical 13 nm gold nanoparticles (AuNPs) and 50 nm silver nanoparticles (AgNPs) on regular glass slides with convective assembly method for SERS based immunoassay for the detection and identification of bacteria. The synthesized NPs are characterized by UV-vis absorption spectroscopy, dynamic light scattering (DLS) and atomic force microscopy (AFM). Colloidal suspensions are concentrated by centrifugation to obtain thin films by the deposition of NPs on a regular glass slide with the convective assembly. The experimental parameters for the convective assembly are optimized by changing of NP concentration, stage velocity and NPs volume dropped between two glass slides. Structural characterization of thin films is performed by AFM and SEM. SERS is also used for the optical characterization of the prepared thin films of NPs. In this study, 4- aminothiophenol (4-ATP) is used as probe molecules to evaluate SERS activity of the thin films depending on the type and concentration of NPs. The results demonstrate that, SERS performances of the thin films are dependent on not only the type of NPs but also it depends on the concentration of NPs which forms thin films. The thin film having highest SERS activity could be used for the SERS-based immunoassays for the detection and identification of bacteria.

  19. Distinctive Characteristics of Educational Donors

    ERIC Educational Resources Information Center

    James, Russell N., III.

    2008-01-01

    Examining the charitable behavior of 56,663 US households, this paper evaluates the distinctive characteristics of educational donors as compared with donors to noneducational charitable organizations and with nondonors. In general, educational donors had significantly greater income, wealth, and education than other donors. Educational donors…

  20. Nanomaterial Labels in Electrochemical Immunosensors and Immunoassays

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2007-12-15

    This article reviews recent advances in nanomaterial labels in electrochemical immunosensors and immunoassays. Various nanomaterial labels are discussed, including colloidal gold/silver, semiconductor nanoparticles, and markers loaded nanocarriers (carbon nanotubes, apoferritin, silica nanoparticles, and liposome beads). The enormous signal enhancement associated with the use of nanomaterial labels and with the formation of nanomaterial–antibody-antigen assemblies provides the basis for ultrasensitive electrochemical detection of disease-related protein biomarkers, biothreat agents, or infectious agents. In general, all endeavors cited here are geared to achieve one or more of the following goals: signal amplification by several orders of magnitude, lower detection limits, and detecting multiple targets.

  1. Fluorescent immunoassay visualization of sorbed pollutants

    SciTech Connect

    Moore, W.K.; Mossman, D.J.; Schwab, A.P.; Feldbush, T.L.

    1994-12-31

    Current methods of detecting sorbed soil pollutants require that the contaminant be extracted from the soil. In an effort to make detection simpler and safer, standard fluorescent immunoassay techniques are being modified to allow fluorescent tags on the pollutant to be viewed and photographed with epifluorescent microscopy. Initial research focuses on detecting chlorinated benzenes on various soil types and developing a technique for tagging these pollutants with appropriate antibodies. This should lead to detection in actual soil cores and a better understanding of how contaminants progress through different soils.

  2. Gliadin Detection in Food by Immunoassay

    NASA Astrophysics Data System (ADS)

    Grant, Gordon; Sporns, Peter; Hsieh, Y.-H. Peggy

    Immunoassays are very sensitive and efficient tests that are commonly used to identify a specific protein. Examples of applications in the food industry include identification of proteins expressed in genetically modified foods, allergens, or proteins associated with a disease, including celiac disease. This genetic disease is associated with Europeans and affects about one in every 200 people in North America. These individuals react immunologically to wheat proteins, and consequently their own immune systems attack and damage their intestines. This disease can be managed if wheat proteins, specifically "gliadins," are avoided in foods.

  3. Systems of donor transfer.

    PubMed

    de Charro, F T; Akveld, H E; Hessing, D J

    1993-10-01

    The development of medical knowledge has resulted in a demand in society for donor organs, but the recruitment of donor organs for transplantation is difficult. This paper aims to provide some general insights into the complex interaction processes involved. A laissez-faire policy, in which market forces are relied on, is not acceptable from an ethical and legal point of view in most western European countries. Especially at the demand side of the exchange of donor organs, commercialism is to be opposed. We judge the use of commercial incentives at the supply side less unacceptable in theory but not feasible in western European countries. Since market forces are deemed unacceptable as instruments for coordinating demand and supply of donor organs, donor procurement has to be considered as a collective good, and therefore governments are faced with the responsibility of making sure that alternative interaction and distribution mechanisms function. The role of organ procurement agencies (OPAs) in societal interaction concerning postmortem organ donation is described using a two-dimensional conceptualisation scheme. Medical aspects of living organ donation are described. An international comparative description of legal systems to regulate living organ donation in western European countries completes this survey. PMID:10129766

  4. Independent donor ethical assessment: aiming to standardize donor advocacy.

    PubMed

    Choudhury, Devasmita; Jotterand, Fabrice; Casenave, Gerald; Smith-Morris, Carolyn

    2014-06-01

    Living organ donation has become more common across the world. To ensure an informed consent process, given the complex issues involved with organ donation, independent donor advocacy is required. The choice of how donor advocacy is administered is left up to each transplant center. This article presents the experience and process of donor advocacy at University of Texas Southwestern Medical Center administered by a multidisciplinary team consisting of physicians, surgeons, psychologists, medical ethicists and anthropologists, lawyers, a chaplain, a living kidney donor, and a kidney transplant recipient. To ensure that advocacy remains fair and consistent for all donors being considered, the donor advocacy team at University of Texas Southwestern Medical Center developed the Independent Donor Ethical Assessment, a tool that may be useful to others in rendering donor advocacy. In addition, the tool may be modified as circumstances arise to improve donor advocacy and maintain uniformity in decision making. PMID:24919733

  5. Managing finances of shipping living donor kidneys for donor exchanges.

    PubMed

    Mast, D A; Vaughan, W; Busque, S; Veale, J L; Roberts, J P; Straube, B M; Flores, N; Canari, C; Levy, E; Tietjen, A; Hil, G; Melcher, M L

    2011-09-01

    Kidney donor exchanges enable recipients with immunologically incompatible donors to receive compatible living donor grafts; however, the financial management of these exchanges, especially when an organ is shipped, is complex and thus has the potential to impede the broader implementation of donor exchange programs. Representatives from transplant centers that utilize the National Kidney Registry database to facilitate donor exchange transplants developed a financial model applicable to paired donor exchanges and donor chain transplants. The first tenet of the model is to eliminate financial liability to the donor. Thereafter, it accounts for the donor evaluation, donor nephrectomy hospital costs, donor nephrectomy physician fees, organ transport, donor complications and recipient inpatient services. Billing between hospitals is based on Medicare cost report defined costs rather than charges. We believe that this model complies with current federal regulations and effectively captures costs of the donor and recipient services. It could be considered as a financial paradigm for the United Network for Organ Sharing managed donor exchange program. PMID:21831153

  6. Microarray-integrated optoelectrofluidic immunoassay system.

    PubMed

    Han, Dongsik; Park, Je-Kyun

    2016-05-01

    A microarray-based analytical platform has been utilized as a powerful tool in biological assay fields. However, an analyte depletion problem due to the slow mass transport based on molecular diffusion causes low reaction efficiency, resulting in a limitation for practical applications. This paper presents a novel method to improve the efficiency of microarray-based immunoassay via an optically induced electrokinetic phenomenon by integrating an optoelectrofluidic device with a conventional glass slide-based microarray format. A sample droplet was loaded between the microarray slide and the optoelectrofluidic device on which a photoconductive layer was deposited. Under the application of an AC voltage, optically induced AC electroosmotic flows caused by a microarray-patterned light actively enhanced the mass transport of target molecules at the multiple assay spots of the microarray simultaneously, which reduced tedious reaction time from more than 30 min to 10 min. Based on this enhancing effect, a heterogeneous immunoassay with a tiny volume of sample (5 μl) was successfully performed in the microarray-integrated optoelectrofluidic system using immunoglobulin G (IgG) and anti-IgG, resulting in improved efficiency compared to the static environment. Furthermore, the application of multiplex assays was also demonstrated by multiple protein detection. PMID:27190571

  7. Fluorimetric Immunoassay for Multianalysis of Aflatoxins

    PubMed Central

    2013-01-01

    A sensitive fluorimetric ELISA was developed for the analysis of aflatoxins. The assay was performed in a 384 microwell plate, wherein high specificity monoclonal antibody against AFM1 (mAb-AFM1) was used as capture antibody and FITC conjugated secondary antibody was used for detection and quantification of the analyte. The linear range of the immunoassay was found to be 6.25–50 pg/mL. AFM1 as low as 1 pg/mL was detected by this method with assay volume 40 μL. The multi-analysis of different aflatoxins was also investigated in the microwell plate, based on the cross-reactivity (CR) approach. Real milk samples were tested along with certified reference material by standard addition method and recovery analysis was done. The mAb-AFM1 showed 23.2% CR with AFB1, 50% CR with respect to AFM2, and least CR towards AFG1 (<1%). Furthermore, mixture analysis of AFM2 and AFB1 was carried out at specific concentrations of AFM1. The advantages of this developed immunoassay are high sensitivity, high throughput, multianalyte detection, versatility, and ease of handling. PMID:24000318

  8. The role of uncertainty regarding the results of screening immunoassays in blood establishments.

    PubMed

    Pereira, Paulo; Westgard, James O; Encarnação, Pedro; Seghatchian, Jerard; de Sousa, Gracinda

    2015-04-01

    The risk of uncertain results in infectious agents' tests is recognized in blood establishments, being particularly evident during the blood donor selection. The current risk-based approaches require risk assessment and "risk-based thinking". Accordingly, the blood establishment should consider the effect of uncertainty in all the technical decisions taken in a screening laboratory. Since the post-transfusion safety is one of the blood establishments' goals, the risk of post-transfusion infection should be evaluated and actions taken to decrease the chance of blood donations validation use false negative results. This article reviews and discusses the sources of uncertainty of infectious agents' reported results in blood establishments. It describes a set of sources of uncertainty that should be considered in screening immunoassay's decisions. The infectious agents' uncertainty concern is critical for reporting reliable results. PMID:25754470

  9. Development of redox-labeled electrochemical immunoassay for polycyclic aromatic hydrocarbons with controlled surface modification and catalytic voltammetric detection.

    PubMed

    Wei, Ming-Yuan; Wen, Shou-Dong; Yang, Xi-Qiang; Guo, Liang-Hong

    2009-05-15

    A redox-labeled direct competitive electrochemical immunoassay for polycyclic aromatic hydrocarbons (PAHs) was developed. A ruthenium tris(bipyridine)-pyrenebutyric acid conjugate was synthesized as the redox-labeled tracer. Its recognition by an anti-PAH monoclonal antibody was confirmed by surface plasmon resonance. In the immunoassay, the antibody was immobilized on (3-glycidoxypropyl)-trimethoxysilane (GPTMS)-modified indium tin oxide (ITO) electrodes. The assay was quantified by measuring the electro-catalytic current of the redox label in an oxalate-containing electrolyte which served as a sacrificial electron donor to amplify the current signal. Formation of GPTMS film on ITO and subsequent antibody immobilization were characterized by X-ray photoelectron spectroscopy (XPS) and electrochemistry. Using a ruthenium tris(bipyridine)-conjugated IgG (IgG-Ru) as the surface-bound redox probe, the highest electrochemical signal was obtained on GPTMS electrodes with 1 h modification. Under the optimized conditions for ITO modification, antibody immobilization and tracer concentration, competition curves for benzo[a]pyrene and pyrenebutyric acid were obtained with a detection limit of 2.4 and 10 ng mL(-1), respectively. The redox-labeled electrochemical immunoassay with signal amplification mechanism offers a potential analytical method for the simultaneous detection of multiple environmental organic pollutants on antibody biochips. PMID:19321333

  10. Rapid quantitation of human epididymis protein 4 in human serum by amplified luminescent proximity homogeneous immunoassay (AlphaLISA).

    PubMed

    Zhao, Hui; Lin, Guanfeng; Liu, Tiancai; Liang, Junyu; Ren, Zhiqi; Liang, Rongliang; Chen, Baihong; Huang, Wenhua; Wu, Yingsong

    2016-10-01

    A sensitive, rapid and homogeneous reaction measurement method for quantitation of human epididymis protein 4 (HE4) in human serum by amplified luminescent proximity homogeneous immunoassay (AlphaLISA) was described. Built on a sandwich-type immunoassay format, analytes in samples were captured by one biotinylated monoclonal antibody combining on the surface of streptavidin coated donor beads, and "sandwiched" by another monoclonal antibody coated on acceptor beads. The coefficient variations of the method were lower than 10%, and the recoveries were in the range of 90-110% for serum samples. A value of 0.88pmol/l was identified as the minimum detectable dose of the present method for HE4. Compared with the results from electrochemiluminescence immunoassay kit (Roche) in 170 serum samples, there was a satisfied correlation coefficient of 0.984. The present assay demonstrated high sensitivity, wider effective detection range and excellent reproducibility for quantitation of HE4 can be useful for early screening and prognosis evaluation of patients with ovarian cancer. PMID:27568283

  11. Element-tagged immunoassay with ICP-MS detection: evaluation and comparison to conventional immunoassays

    PubMed Central

    Razumienko, Eva; Ornatsky, Olga; Kinach, Robert; Milyavsky, Michael; Lechman, Eric; Baranov, Vladimir; Winnik, Mitchell A.; Tanner, Scott D.

    2008-01-01

    We have investigated the possibility of using element-tagged antibodies for protein detection and quantification in microplate format using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and compared the results to conventional immunoassays, such as Enzyme-Linked Immunosorbent Assay (ELISA) and Western blotting. The technique was further employed to detect low levels and measure DNA-binding activity of transcription factor p53 in leukemia cell lysates through its interaction with immobilized oligonucleotides and recognition by element-tagged antibodies. The advantages of ICP-MS detection for routine performance of immunoassays include increased sensitivity, wide dynamic range, minimal interference from complex matrices, and high throughput. Our approach advances the ICP-MS technology and demonstrates its applicability to proteomic studies through the use of antibodies directly labeled with polymer tags bearing multiple atoms of lanthanides. Development of this novel methodology will enable fast and quantitative identification of multiple analytes in a single well. PMID:18456275

  12. An on-bacterium flow cytometric immunoassay for protein quantification.

    PubMed

    Lan, Wen-Jun; Lan, Wei; Wang, Hai-Yan; Yan, Lei; Wang, Zhe-Li

    2013-09-01

    The polystyrene bead-based flow cytometric immunoassay has been widely reported. However, the preparation of functional polystyrene bead is still inconvenient. This study describes a simple and easy on-bacterium flow cytometric immunoassay for protein quantification, in which Staphylococcus aureus (SAC) is used as an antibody-antigen carrier to replace the polystyrene bead. The SAC beads were prepared by carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling, paraformaldehyde fixation and antibody binding. Carcinoembryonic antigen (CEA) and cytokeratin-19 fragment (CYFRA 21-1) proteins were used as models in the test system. Using prepared SAC beads, biotinylated proteins, and streptavidin-phycoerythrin (SA-PE), the on-bacterium flow cytometric immunoassay was validated by quantifying CEA and CYFRA 21-1 in sample. Obtained data demonstrated a concordant result between the logarithm of the protein concentration and the logarithm of the PE mean fluorescence intensity (MFI). The limit of detection (LOD) in this immunoassay was at least 0.25 ng/ml. Precision and accuracy assessments appeared that either the relative standard deviation (R.S.D.) or the relative error (R.E.) was <10%. The comparison between this immunoassay and a polystyrene bead-based flow cytometric immunoassay showed a correlation coefficient of 0.998 for serum CEA or 0.996 for serum CYFRA 21-1. In conclusion, the on-bacterium flow cytometric immunoassay may be of use in the quantification of serum protein. PMID:23739299

  13. Dialing for Donors

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    When times get tough, grown children often turn to their parents for help--for some extra cash, even somewhere to stay. For colleges and universities, that role is filled by alumni donors. In 2011, with education budgets slashed across the country, giving accounted for 6.5 percent of college expenditures, according to the Council for Aid to…

  14. Understanding donors' motivations: a study of unrelated bone marrow donors.

    PubMed

    Switzer, G E; Dew, M A; Butterworth, V A; Simmons, R G; Schimmel, M

    1997-07-01

    Medical advances in bone marrow transplantation techniques and immunosuppressive medications have dramatically increased the number of such transplants performed each year, and consequently, the demand for bone marrow from unrelated donors. Although physiological aspects of bone marrow donation have been thoroughly investigated, very few studies have examined psychosocial factors that may impact individuals' donation decisions and outcomes. To examine one particular set of donor psychosocial issues, this study investigated motives for bone marrow donation among 343 unrelated bone marrow donors who donated through the National Marrow Donor Program. Six distinct types of donor motives were identified from open-ended questionnaire responses. Donors most frequently reported motives reflecting some awareness of both the costs (to themselves) and potential benefits (to themselves and the recipient) of donation. A desire to act in accordance with social or religious precepts, expected positive feelings about donating, empathy for the recipient, and the simple desire to help another person were also commonly cited reasons for donating. Among a series of donor background characteristics, donors' gender was the variable most strongly associated with motive type; women were most likely to cite expected positive feelings, empathy, and the desire to help someone. Central study findings indicated that donor motives predicted donors reactions to donation even after the effects of donor background characteristics (including gender) were controlled. Donors who reported exchange motives (weighing costs and benefits) and donors who reported simple (or idealized) helping motives experienced the donation as less positive in terms of higher predonation ambivalence and negative postdonation psychological reactions than did remaining donors. Donors who reported positive feeling and empathy motives had the most positive donation reactions in terms of lower ambivalence, and feeling like

  15. Self-concentrating buoyant glass microbubbles for high sensitivity immunoassays.

    PubMed

    Juang, Duane S; Hsu, Chia-Hsien

    2016-02-01

    Here, we report the novel application of a material with self-concentrating properties for enhancing the sensitivity of immunoassays. Termed as glass microbubbles, they are antibody functionalized buoyant hollow glass microspheres that simultaneously float and concentrate into a dense monolayer when dispensed in a liquid droplet. This self-concentrating charactaristic of the microbubbles allow for autonomous signal localization, which translates to a higher sensitivity compared to other microparticle-based immunoassays. We then demonstrated a "microbubble array" platform consisting of the glass microbubbles floating in a microfluidic liquid hemisphere array for performing multiplex immunoassays. PMID:26620967

  16. Immunoassay procedures for fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Ligler, Frances S.

    1988-04-01

    There is an increasing need for the development of an ultrasensitive immunoassay for use with fiber optic sensors. These detection systems can be used for such applications as disease diagnosis, detection of chemical and biological warfare agents or drugs of abuse, pollution control, therapeutic monitoring, and explosive detection. This specific program is designed to produce generic chemistries for use with existing fiber optic-based sensors to detect pathogens of particular threat to Army personnel as determined by USAMRIID. The detection system under development involves the attachment of antibodies to an optical fiber at high density. In addition, the immobilization must be achieved in a way which retains the antibody's ability to bind antigen. The functionality of the antibody will be tested through the binding of a labelled antigen. In the future, this assay could incorporate the antibodies developed by the Army for pathogens of particularly military concern.

  17. Application of enzyme immunoassays to coagulation testing.

    PubMed

    Amiral, J; Adalbert, B; Adam, M

    1984-09-01

    Enzyme immunoassays are very useful for the detection of low concentrations of coagulation proteins and pathological markers in plasma. Analytes in the ng/mL range are measurable with good reproducibility with intra- and interassay CVs of less than 5% to 10%. "Sandwich" methods have been developed for von Willebrand factor (plasma concentration about 8 micrograms/mL, Factor IX (5 micrograms/mL), protein C (4 micrograms/mL), and Factor X (10 micrograms/mL). However, this technique is only suitable for macromolecules; for low-molecular-mass peptides such as fibrinopeptide A a competitive method is used. Normal concentrations of fibrinopeptide A are below 3 ng/mL, with greater values suggesting in vivo generation of thrombin; thus this test is quite useful in detecting thrombosis. Reagents for both the sandwich and competitive methods are commercially available and cost effective, and have a longer shelf-life than those for radioimmunoassays. PMID:6380814

  18. Neutralization enzyme immunoassay for influenza virus.

    PubMed Central

    Benne, C A; Harmsen, M; De Jong, J C; Kraaijeveld, C A

    1994-01-01

    A neutralization enzyme immunoassay (N-EIA) was developed for the detection of antibody titer rises in sera of patients infected with influenza A (H3N2) virus. In this N-EIA, a selected strain of influenza A (H3N2) virus was added to monolayers of LLC-MK2 cells in microtiter plates. After 24 h, the replicated virus could be demonstrated with a virus-specific enzyme-labeled monoclonal antibody. Preincubation of the influenza virus with convalescent-phase sera of patients infected with influenza A (H3N2) virus resulted 1 day later in decreased absorbance values that could be used for calculation of neutralization titers. From use of paired serum samples from 10 patients with a history of flu-like symptoms, the results obtained with N-EIA correlated well (r = 0.83) with those of the standard hemagglutination inhibition test. PMID:8027355

  19. Nanoparticles for Enhanced Sensitivity in Electrochemical Immunoassays

    SciTech Connect

    Lin, Yuehe; Wang, Jun; Wang, Hua; Wu, Hong; Tang, Zhiwen

    2008-10-12

    In this manuscript, we report on electrochemical biosensors based on various nanoparticles (NPs) as labels for sensitive detection of protein biomarkers. We used silica nanoparticle as a carrier to loading a large amount of electroactive species such as poly(guanine) for sensitive immunoassay of tumor necrosis factor-alpha (TNF-a). We took the advantages of the unique hollow structure and reconstruction properties of apoferritin to prepare Cd3(PO4)2 nanoparticles as labels for sensitive assay of TNF-a. A novel immunochromatographic/electro-chemical biosensor based on quantum dots as labels has also been developed for rapid and sensitive detection of prostate-specific antigen (PSA) in human serum. These biosensors are quite sensitive with the detection limit at pM level and these approaches based on nanoparticle labels offer a new avenue for sensitive detection of protein biomarkers.

  20. "Smart" mobile affinity matrix for microfluidic immunoassays.

    PubMed

    Malmstadt, Noah; Hoffman, Allan S; Stayton, Patrick S

    2004-08-01

    There is a current need for simple methods for immobilizing biomolecules within microfluidic channels. Here, a technique is reported for reversibly immobilizing immunoassay components in a channel zone that can be simply controlled by integrated heating elements. Latex beads were modified with the temperature-responsive polymer poly(N-isopropylacrylamide)(PNIPAAm) and co-modified with biotinylated poly(ethylene glycol)(PEG). PNIPAAm undergoes a hydrophilic-to-hydrophobic transition when the temperature is raised above the lower critical solution temperature (LCST)( approximately 28 degrees C in the solutions used here). This reversible transition drives the aggregation and dis-aggregation of the modified beads in heated zones within poly(ethylene terephthalate)(PET) microchannels. Biotinylated monoclonal antibodies for the drug digoxin were bound via streptavidin to the biotin-PEG-coated beads. These antibody-functionalized beads were then reversibly immobilized by aggregation and hydrophobic adhesion to the surface of PET microfluidic channels in response to a thermal stimulus. The antibodies on the beads immobilized in the channel were shown to bind digoxin and a competitor fluorescent ligand from a flow stream in a quantitative competitive assay format that reported the digoxin concentration. The antibodies could be replenished for each immunoassay trial, using the reversible, temperature-controlled immobilization process. This technique allows reagent immobilization immediately prior to an analytical procedure, following the removal of previously utilized beads, guaranteeing fresh and active immobilized biomolecules. Furthermore, it provides a simple approach to multiplexing through the simultaneous or sequential injection of different antibody-coated bead species, potentially at multiple sites in the integrated device channels. PMID:15269814

  1. Being a Living Donor: Risks

    MedlinePlus

    ... surgical risks and long term complications: Long-Term Organ Specific Donor Complications Kidney Hypertension Kidney failure Proteinuria Lung Intra- ... Vancouver Forum on the care of the live organ donor: lung, liver, pancreas, and intestine data and medical ...

  2. Donor commitment and patient needs.

    PubMed

    Bakken, R; van Walraven, A-M; Egeland, T

    2004-01-01

    The article discusses views and recommendations of the World Marrow Donor Association concerning ethical issues related to the donation of hematopoietic stem cell products with respect to recruitment, evaluation, workup, and follow-up of unrelated donors. Particular emphasis is placed upon commitment of individual donors, in particular, with respect to the needs of patients to find HLA-matched donors, who may be asked to donate stem cell and other cell products more than once for given patients. PMID:14628078

  3. Comparison of immunoassay screening tests and LC-MS-MS for urine detection of benzodiazepines and their metabolites: results of a national proficiency test.

    PubMed

    Bertol, Elisabetta; Vaiano, Fabio; Borsotti, Maurizio; Quercioli, Massimo; Mari, Francesco

    2013-01-01

    For most diverse purposes, different immunoassay (IA) screening methods are usually used to detect benzodiazepines and their metabolites in urine. In this study, we compared the main IAs used in forensic toxicology (Cloned Enzyme Donor Immunoassay, CEDIA®; Enzyme-Multiplied Immunoassay Technique, EMIT®; Fluorescent Polarization ImmunoAssay, FPIA®; Kinetic Interaction of Microparticles in Solution, KIMS® and Immunochromatographic Techniques, IMC) with liquid chromatography-tandem mass spectrometry (LC-MS-MS). Twelve urine specimens were analyzed by 178 laboratories in Italy that participated in a National Proficiency Test, providing both qualitative and semi-quantitative results. Each IA was evaluated by the parameters: true positive, true negative, false positive (FP), false negative (FN), sensitivity (SENS), specificity (SPEC), positive predictive value, negative predictive value (NPV) and accuracy. SPEC was affected by a high FP rate for all IAs. The lowest SENS and NPV were provided by FPIA due to a high number of FN cases. Comparing IA semi-quantitative data with LC-MS-MS results, an overestimation of benzodiazepine amount is noted. This paper draws attention to the problem of the careless use of IA tests for forensic purposes as they may provide FP and/or FN results that can lead to errors of great severity. PMID:23943436

  4. Why Minority Donors Are Needed

    MedlinePlus

    ... Español Search Register with your state as an Organ Donor Home Why Donate Becoming a Donor About Donation & ... Why Donate RELATED INFORMATION Minority Focused Grantee Publications Organ Donation Process Enrolling as a Donor Trying to Save a Life Testing for Brain ...

  5. DETECTION OF ROTAVIRUS WITH A NEW POLYCLONAL ANTIBODY ENZYME IMMUNOASSAY (ROTAZYME 2) AND A COMMERCIAL LATEX AGGLUTINATION TEXT (ROTALEX): COMPARISON WITH A MONOCLONAL ANTIBODY ENZYME IMMUNOASSAY

    EPA Science Inventory

    A total of 176 human fecal specimens were examined for the presence of rotavirus using four different assays: a monoclonal antibody enzyme immunoassay; the original polyclonal antibody enzyme immunoassay marketed by Abbott Laboratories, Chicago, IL (Rotazyme I); a modification of...

  6. Syphilis detection: evaluation of serological screening and pilot reverse confirmatory assay algorithm in blood donors.

    PubMed

    Sommese, Linda; Paolillo, Rossella; Sabia, Chiara; Costa, Dario; De Pascale, Maria Rosaria; Iannone, Carmela; Esposito, Antonella; Schiano, Concetta; Napoli, Claudio

    2016-07-01

    Serological assays are still considered the most useful tests in the diagnosis of syphilis. Since no single serological assay is able to provide a satisfactory result, in our laboratory we have evaluated the usefulness of a commercially-available immunoblot to diagnose syphilis infection among blood donors. From October 2012 to June 2013, 4572 blood donors were screened for syphilis with an automated chemiluminescent microparticle immunoassay (CMIA). To confirm the presence of treponemal antibodies, CMIA-reactive sera were tested by standard Treponema pallidum haemagglutination assay (TPHA). In addition, an alternative confirmatory test - the immunoblot INNO-LIA assay was introduced in our laboratory. Since two additional positives among CMIA-reactive-TPHA-negative samples were found, we concluded that the INNO-LIA immunoblot allowed a better detection of syphilis compared to TPHA. A confirmatory strategy based on the use of two treponemal assays could meet the screening requirements for blood donors as well as in our centre. PMID:26068964

  7. Detection of narcotics with an immunoassay film badge

    SciTech Connect

    Lukens, H.R.

    1993-12-31

    Efficient personnel performance, a major requirement for a safe nuclear industry, is jeopardized where personnel use narcotics. However, detection of narcotics at nuclear plants is a challenge. The unique specificity and sensitivity of an immunoassay has been implemented in the form of a small, dry immunoassay film badge (IFB) for the detection of vapors emitted by narcotics. The device is suitable as an area monitor, and its characteristics are suitable for use as a breath monitor for the detection of drug use.

  8. Confidentiality and American semen donors.

    PubMed

    Karow, A M

    1993-01-01

    Most American donor insemination programs include a policy of complete confidentiality concerning the donor of the semen. This is the result of a long legal tradition of American constitutional law. However, some slight abridgement of this body of legal decisions might be very much in the best interests of children arising from donor insemination, and even--in most cases, in fact--the donors themselves. With regard to the children, the factors involved are both those of genetic counseling, should the need arise, and psychological development. Of course, as at present, the donor must be relieved of all responsibility, both legal and financial. PMID:8348162

  9. Blood Donor Management in China

    PubMed Central

    Shi, Ling; Wang, Jingxing; Liu, Zhong; Stevens, Lori; Sadler, Andrew; Ness, Paul; Shan, Hua

    2014-01-01

    Summary Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China. PMID:25254023

  10. Blood donor management in china.

    PubMed

    Shi, Ling; Wang, Jingxing; Liu, Zhong; Stevens, Lori; Sadler, Andrew; Ness, Paul; Shan, Hua

    2014-07-01

    Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China. PMID:25254023

  11. The mystifying nomenclature of cardiac troponin immunoassays.

    PubMed

    Lippi, Giuseppe

    2014-06-01

    The laboratory assessment of cardiospecific troponins(s) represents the cornerstone for the diagnosis of acute coronary syndrome (ACS). Although troponin immunoassays are classified according to either analytical imprecision or percentage of measurable values in a presumably healthy population, it is rather clear that the nomenclature of commercial methods according to these systems of classification carries several drawbacks. The leading problems in classification according to imprecision are represented by the arbitrarity of optimal imprecision threshold, the uncertain correspondence between analytical performance and clinical outcomes and the improper use of terms, which has also been magnified by the lack of specific focus on this topic by regulating bodies such as the US Food and Drug Administration (FDA) and the European Union. Additional issues emerging from classification according to percentage of measurable values include the characterization of healthy population, the variation of values according to age, gender and race, as well as the influence of comorbidities. Considering that what really matters from a clinical standpoint is the clinical performance of the assay rather than the claimed analytical characteristics, it seems reasonable at this point in time to introduce a paradigm shift and gradually abandon the former analytical classification in favour of a different approach, preferable based on clinical outcomes. PMID:24588414

  12. Enzyme immunoassay for carminic acid in foods.

    PubMed

    Yoshida, A; Takagaki, Y; Nishimune, T

    1995-01-01

    A competitive enzyme immunoassay (EIA) for carminic acid was investigated. Monoclonal anticarminic acid antibody was obtained from A/J mice immunized with carminic acid-human immunoglobulin G (IgG) conjugate. Carminic acid was extracted with distilled water from beverage, jelly, candy, pasta sauce, yogurt, or ice cream samples. Ham or fish paste samples were digested with pronase, then carminic acid was extracted from samples with sodium hydroxide solution. The extract was diluted more than 10-fold with 1% gelatin in borate buffer solution. Microtiter plates were coated with carminic acid-bovine serum albumin (BSA) conjugate or just BSA. Goat anti-mouse IgG(H+L)-peroxidase complex was used as a second antibody, and 3,3',5,5'-tetramethylbenzidine was used as a substrate for the peroxidase. The working range for quantitative analysis was 0.3-10 ng/mL, and the detection limit was 0.2 micrograms/g original sample. Recoveries of carminic acid by this assay were > 95% for milk beverage and jelly, and > 85% for yogurt and fish paste. Carminic acid was detected in 7 of 26 red-colored commercial food products and ranged from 3.5 to 356 micrograms/g. This EIA system also responded to the structural analogue of carminic acid, laccaic acid. PMID:7756895

  13. Clinical evaluation of teicoplanin fluorescence polarization immunoassay.

    PubMed Central

    Rybak, M J; Bailey, E M; Reddy, V N

    1991-01-01

    A teicoplanin fluorescence polarization immunoassay (FPIA) developed by International BioClinical (IBC) was evaluated by using serum samples from patients who had been receiving teicoplanin at Detroit Receiving Hospital (DRH) as part of a clinical investigation. Patient samples collected over a 1-year span were assayed at DRH and at IBC, and the results were compared with those of a standard microbiological assay performed at Merrell Dow Research Institute, Indianapolis, Ind. The FPIA has a rapid turnaround time (circa 20 min), utilizes small sample volumes (less than 100 microliters) and is sensitive and accurate in determining concentrations in the range of 5 to 100 micrograms/ml. The intra-assay and interassay coefficient of variation for controls (7, 35, and 75 micrograms/ml) was less than or equal to 13%. Concentrations greater than 100 micrograms/ml must be diluted prior to the assay, which may introduce additional error in determination. The FPIA compared well with the bioassay (r = 0.901) for 193 clinical samples. The results obtained utilizing the FPIA system were reproducible at two different sites, as illustrated by the high degree of correlation between the results at DRH and IBC (r = 0.92). There was less than 7% interference noted when teicoplanin was assayed in the presence of other antibiotics. Patient samples stored for up to 1 year retained their potency: the mean recovery rate in these samples was 107%. The FPIA should be useful for monitoring and adjusting teicoplanin dosage regimens in patients. PMID:1834014

  14. Multiplex lateral flow immunoassay for mycotoxin determination.

    PubMed

    Song, Suquan; Liu, Na; Zhao, Zhiyong; Njumbe Ediage, Emmanuel; Wu, Songling; Sun, Changpo; De Saeger, Sarah; Wu, Aibo

    2014-05-20

    A new lateral flow immunoassay (LFA) is proposed for qualitative and/or semiquantitative determination of aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON), and their analogues (AFs, ZEAs, DONs) in cereal samples. Each of the mycotoxin specific antibody was class specific and there was no cross reactivity to other groups of compounds. The visual limits of detection (vLOD) of the strip were 0.03, 1.6, and 10 μg/kg for AFB1, ZEA and DON, respectively. The calculated limits of detection (cLOD) were 0.05, 1, and 3 μg/kg, respectively. Meanwhile the cutoff values were achieved at 1, 50, and 60 μg/kg for AFB1, ZEA and DON, respectively. Recoveries ranged from 80% to 122% and RSD from 5% to 20%. Both the vLOD and cLOD for the three mycotoxins were lower than the EU maximum levels. Analysis of naturally contaminated maize samples resulted in a good agreement between the multiplex LFA and LC-MS/MS (100% for DONs and AFs, and 81% for ZEAs). Careful analysis of the results further explained the general overestimation of LFA compared to chromatographic methods for quantification of mycotoxins. PMID:24745689

  15. Vertical flow immunoassay (VFA) biosensor for a rapid one-step immunoassay.

    PubMed

    Oh, Young Kyoung; Joung, Hyou-Arm; Kim, Sanghyo; Kim, Min-Gon

    2013-03-01

    A highly rapid, one-step immunoassay of high sensitivity C-reactive protein (hsCRP) using a biosensor with a vertical flow immunoassay (VFA) was developed. The VFA biosensor was primarily composed of a sample pad, conjugate pad, FTH film and nitrocellulose (NC) membrane, which were all vertically stacked upon one another. Anti-hsCRP and secondary antibodies were consecutively immobilized on the NC membrane at the position below the holes. Gold nanoparticles (AuNPs) conjugated with another anti-hsCRP antibody were encapsulated in the conjugation pad. Various assay conditions, including the size of the hole and the sample volume, were optimized. Under optimized conditions, hsCRP concentrations from 0.01 to 10 μg mL(-1) were detected within 2 min. In comparison with a lateral flow assay (LFA) system, the VFA sensor showed a gradual increase of signal in a concentration-dependent manner without a hook effect in the tested range. PMID:23303290

  16. Capillary Isoelectric Focusing Immunoassay for Fat Cell Differentiation Proteomics

    PubMed Central

    Johlfs, Mary G.; Gorjala, Priyatham; Urasaki, Yasuyo; Le, Thuc T.; Fiscus, Ronald R.

    2015-01-01

    Profiling cellular proteome is critical to understanding signal integration during cell fate determination. In this study, the capability of capillary isoelectric focusing (cIEF) immunoassays to detect post-translational modifications (PTM) of protein isoforms is demonstrated. cIEF immunoassays exhibit protein detection sensitivity at up to 5 orders of magnitude higher than traditional methods. This detection ultra-sensitivity permits proteomic profiling of several nanograms of tissue samples. cIEF immunoassays are employed to simultaneously profile three protein kinases during fat cell differentiation: cGMP-dependent protein kinase type I (PKG-I) of the nitric oxide (NO) signaling pathway, protein kinase B (Akt) of the insulin signaling pathway, and extracellular signal-regulated kinase (ERK) of the mitogen-activated protein kinase (MAPK) signaling pathway. Interestingly, a switch in the expression level of PKG- isoforms is observed during fat cell differentiation. While both PKG-Iα and PKG-Iβ isoforms are present in preadipocytes, only PKG-Iβ isoform is expressed in adipocytes. On the other hand, the phosphorylation level increases for Akt while decreases for ERK1 and ERK2 following the maturation of preadipocytes into adipocytes. Taken together, cIEF immunoassay provides a highly sensitive means to study fat cell differentiation proteomics. cIEF immunoassay should be a powerful proteomics tool to study complex protein signal integration in biological systems. PMID:26132171

  17. Immunoassay Analysis of Kanamycin in Serum Using the Tobramycin Kit.

    PubMed

    Dijkstra, J A; Voerman, A J; Greijdanus, B; Touw, D J; Alffenaar, J W C

    2016-08-01

    Kanamycin is one of the aminoglycosides used in the treatment of multidrug-resistant tuberculosis. Blood concentrations of kanamycin are predictive for the treatment efficacy and the occurrence of side effects, and dose adjustments can be needed to optimize therapy. However, an immunoassay method for the quantification of kanamycin is not commercially available. We modified the existing tobramycin immunoassay to analyze kanamycin. This modified method was tested in a concentration range of 0.3 to 80.0 mg/liter for inaccuracy and imprecision. In addition, the analytical results of the immunoassay method were compared to those obtained by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method using Passing and Bablok regression. Within-day imprecision varied from 2.3 to 13.3%, and between-day imprecision ranged from 0.0 to 11.3%. The inaccuracy ranged from -5.2 to 7.6%. No significant cross-reactivity with other antimicrobials and antiviral agents was observed. The results of the modified immunoassay method were comparable with the LC-MS/MS analytical outcome. This new immunoassay method enables laboratories to perform therapeutic drug monitoring of kanamycin without the need for complex and expensive LC-MS/MS equipment. PMID:27185806

  18. Immunoassay as an analytical tool in agricultural biotechnology.

    PubMed

    Grothaus, G David; Bandla, Murali; Currier, Thomas; Giroux, Randal; Jenkins, G Ronald; Lipp, Markus; Shan, Guomin; Stave, James W; Pantella, Virginia

    2006-01-01

    Immunoassays for biotechnology engineered proteins are used by AgBiotech companies at numerous points in product development and by feed and food suppliers for compliance and contractual purposes. Although AgBiotech companies use the technology during product development and seed production, other stakeholders from the food and feed supply chains, such as commodity, food, and feed companies, as well as third-party diagnostic testing companies, also rely on immunoassays for a number of purposes. The primary use of immunoassays is to verify the presence or absence of genetically modified (GM) material in a product or to quantify the amount of GM material present in a product. This article describes the fundamental elements of GM analysis using immunoassays and especially its application to the testing of grains. The 2 most commonly used formats are lateral flow devices (LFD) and plate-based enzyme-linked immunosorbent assays (ELISA). The main applications of both formats are discussed in general, and the benefits and drawbacks are discussed in detail. The document highlights the many areas to which attention must be paid in order to produce reliable test results. These include sample preparation, method validation, choice of appropriate reference materials, and biological and instrumental sources of error. The article also discusses issues related to the analysis of different matrixes and the effects they may have on the accuracy of the immunoassays. PMID:16915826

  19. High-Throughput Optical Sensing Immunoassays on Smartphone.

    PubMed

    Wang, Li-Ju; Sun, Rongrong; Vasile, Tina; Chang, Yu-Chung; Li, Lei

    2016-08-16

    We present an optical sensing platform on a smartphone for high-throughput screening immunoassays. For the first time, a designed microprism array is utilized to achieve a one-time screening of 64 samples. To demonstrate the capability and the reliability of this optical sensing platform on smartphone, human interleukin 6 (IL-6) protein and six types of plant viruses are immunoassayed. The ability of quantification is shown by a sigmoidal dose-response curve fitting to analyze IL-6 protein. The accuracy in measuring the concentrations of IL-6 protein achieves 99.1%. On the other hand, to validate on-field immunoassays by our device, a total of 1030 samples are assayed using three immunoassay methods to detect six types of plant viruses. The accuracy is up to 96.2-99.9%; in addition, there is a high degree of agreement with lab instruments. The total cost for this high-throughput optical screening platform is ∼$50 USD. The reading time is only 2 s for 64 samples. The size is just as big as a portable hard drive. Our optical sensing platform on the smartphone offers a route toward in situ high-throughput screening immunoassays for viruses, pathogens, biomarkers, and toxins by decentralizing laboratory tests. With this mobile point-of-care optical platform, the spread of disease can be timely stopped within a very short turnaround time. PMID:27434250

  20. Organ Donor FAQ's: Who Can Be a Donor

    MedlinePlus

    ... citizens have been organ donors. Can non-resident aliens donate and receive organs? Non-resident aliens can both donate and receive organs in the ... the 12,375 organ donors were non-resident aliens. In this same year, 259 (1%) of the ...

  1. Compact quantum dot-antibody conjugates for FRET immunoassays with subnanomolar detection limits.

    PubMed

    Mattera, Lucia; Bhuckory, Shashi; Wegner, K David; Qiu, Xue; Agnese, Fabio; Lincheneau, Christophe; Senden, Tim; Djurado, David; Charbonnière, Loïc J; Hildebrandt, Niko; Reiss, Peter

    2016-06-01

    A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields ultra-compact, stable, and highly luminescent antibody-QD conjugates suitable for use in FRET immunoassays. Hydrophobic InPZnS/ZnSe/ZnS (emission wavelength: 530 nm), CdSe/ZnS (605 nm), and CdSeTe/ZnS (705 nm) QDs were surface functionalized with zwitterionic penicillamine, enabling aqueous phase transfer under conservation of the photoluminescence properties. Post-functionalization with a heterobifunctional crosslinker, containing a lipoic acid group and a maleimide function, enabled the subsequent coupling to sulfhydryl groups of proteins. This was demonstrated by QD conjugation with fragmented antibodies (F(ab)). The obtained F(ab)-QD conjugates range among the smallest antibody-functionalized nanoprobes ever reported, with a hydrodynamic diameter <13 nm, PL quantum yield up to 66% at 705 nm, and colloidal stability of several months in various buffers. They were applied as FRET acceptors in homogeneous, time-gated immunoassays using Tb-antibodies as FRET donors, both coupled by an immunological sandwich complex between the two antibodies and a PSA (prostate specific antigen) biomarker. The advantages of the compact surface coating for FRET could be demonstrated by an 6.2 and 2.5 fold improvement of the limit of detection (LOD) for PSA compared to commercially available hydrophilic QDs emitting at 605 and 705 nm, respectively. While the commercial QDs contain identical inorganic cores responsible for their fluorescence, they are coated with a comparably thick amphiphilic polymer layer leading to much larger hydrodynamic diameters (>26 nm without biomolecules). The LODs of 0.8 and 3.7 ng mL(-1) obtained in 50 μL serum samples are below the clinical cut-off level of PSA (4 ng mL(-1)) and demonstrate their direct applicability in clinical diagnostics. PMID:27188210

  2. An internal standard approach for homogeneous TR-FRET immunoassays facilitates the detection of bacteria, biomarkers, and toxins in complex matrices.

    PubMed

    Cohen, Noam; Zahavy, Eran; Zichel, Ran; Fisher, Morly

    2016-07-01

    The recent development of a homogeneous time-resolved Förster resonance energy transfer (TR-FRET) immunoassay enables one-step, rapid (minutes), and direct detection compared to the multistep, time-consuming (hours), heterogeneous ELISA-type immunoassays. The use of the time-resolved effect of a donor lanthanide complex with a delay time of microseconds and large Stokes shift enables the separation of positive signals from the background autofluorescence of the sample. However, this study shows that the sample matrices directly interfere with donor fluorescence and that interference cannot be eliminated by time-resolved settings alone. Moreover, the reduction in donor emission did not appear to be equivalent to the reduction in acceptor emission, resulting in incorrect FRET signal measurements. To overcome this limitation, an internal standard approach was developed using an isotype control antibody. This new approach was used to develop TR-FRET assays for rapid detection (15-30 min) of Bacillus anthracis spores and botulinum toxin (type E) in beverages, which are major concerns in bioterrorism involving deliberate food contamination. Additionally, we demonstrate the detection of B. anthracis-secreted protective antigen (PA) and the Yersinia pestis-secreted markers F1 and LcrV in blood cultures, which are early markers of bacteremia in infected hosts following a possible bioterror attack. The use of an internal standard enables the calculation of correct ΔF values without the need for an external standard. Thus, the use of the internal standard approach in homogeneous immunoassays facilitates the examination of any sample regardless of its origin, and therefore expands the applicability of TR-FRET assays for complex matrices. PMID:27236318

  3. PRNP variants in goats reduce sensitivity of detection of PrPSc by immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays are extensively utilized in disease diagnostics with monoclonal antibodies serving as critical tools within the assay. Detection of scrapie in sheep and goats relies heavily on immunoassays including immunohistochemistry, western blotting, and ELISA. In the United States, regulatory tes...

  4. SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION (SITE) REPORT FOR THE WESTINGHOUSE BIOANALYTICAL SYSTEMS PENTACHLOROPHENOL (PCP) IMMUNOASSAYS

    EPA Science Inventory

    The results of the demonstration of two Westinghouse Bio-Analytic Systems (WBAS) immunoassay technologies are described in this report. The immunoassays measure parts per billion concentrations of pentachlorophenol in environmental water samples. The study was conducted under the...

  5. SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION PROGRAM DEMONSTRATION PLAN FOR WESTINGHOUSE BIO-ANALYTIC SYSTEMS PENTACHLOROPHENOL IMMUNOASSAYS

    EPA Science Inventory

    This plan provides a detailed design and description of the demonstration and evaluation program for the Westinghouse Bio-Analytic Systems immunoassay technologies specific for the analysis of pentachlorophenol. he immunoassays measure parts per billion concentrations of pentachl...

  6. The Effects of Sample Matrices on Immunoassays to Detect Microcystin-LR in Water

    EPA Science Inventory

    Abstract: Immunoassays are widely used biochemical techniques to detect microcystins in environmental samples. The use of immunoassays for the detection of microcystins is vulnerable to matrix components and other interferents. This study is an evaluation of the effects of interf...

  7. A Wash-Free Homogeneous Colorimetric Immunoassay Method

    PubMed Central

    Liu, Huiqiao; Rong, Pengfei; Jia, Hongwei; Yang, Jie; Dong, Bo; Dong, Qiong; Yang, Cejun; Hu, Pengzhi; Wang, Wei; Liu, Haitao; Liu, Dingbin

    2016-01-01

    Rapid and convenient biosensing platforms could be beneficial to timely diagnosis and treatment of diseases in virtually any care settings. Sandwich immunoassays, the most commonly used methods for protein detection, often rely on expensive tags such as enzyme and tedious wash and incubation procedures operated by skilled labor. In this report, we revolutionized traditional sandwich immunoassays by providing a wash-free homogeneous colorimetric immunoassay method without requirement of any separation steps. The proposed strategy was realized by controlling the growth of gold nanoparticles (AuNPs) to mediate the interparticle spacing in the protein-AuNP oligomers. We have demonstrated the successful in vitro detection of cancer biomarker in serum samples from patients with high clinical sensitivity and specificity. PMID:26722373

  8. Potential applications of immunoassays in studies of flatfish recruitment

    NASA Astrophysics Data System (ADS)

    Feller, Robert J.

    The fisheries recruitment-stock problem, a lack of correlation between measures of reproductive output of the parent stock and recruitment to the fishery, has several potential biotic and abiotic causes. Immunoassays may be useful in examining several aspects of this and several other problems in flatfish ecology: stock identification, parasitism and disease, and trophic interactions. Given stage-specific antisera capable of recognozing antigenic moieties of, for instance, eggs, larvae, or newly-settled juveniles, it is possible to screen stomach contents of many putative predators ( e.g., shrimp or crabs) rapidly for the presence and amounts of platfish prey. This trophic application of immunological methods has great promise for measuring loss of potential recruits to predation. All immunoassays are limited by the quality of antisera used and the researcher's ability to interpret quantitative data in an ecologically meaningful way. Key references for applications of immunoassays in fish-related questions are provided with recommendations for their utilization.

  9. Detection of bound residues in soils by sandwich-immunoassay

    SciTech Connect

    Dosch, M.; Weller, M.G.; Niessner, R.

    1995-12-31

    Immunoassays are useful analytical instruments for the detection of many environmental compounds. This method was not introduced for the detection of non-extractable compounds in soil. So-called ``bound residues`` consist of a soil component, e.g. humic acids and an irreversibly bound pollutant. Because of the complexity of those macromolecules conventional analytical methods in general do not work. Enzyme immunoassays, in contrast, seem to have a large potential for applications and further developments in this field. The use of antibodies with high affinity to the analytes makes a selective detection of environmental pollutants possible. With the development of an enzyme-labeled sandwich-immunoassay polycyclic aromatic hydrocarbons (PAHs) irreversibly bound to humic acids were determined for the first time.

  10. Detection of bound residues in soils by sandwich-immunoassay

    NASA Astrophysics Data System (ADS)

    Dosch, M.; Weller, Michael G.; Niessner, Reinhard

    1995-10-01

    Immunoassays are useful analytical instruments for the detection of many environmental compounds. This method is now introduced for the detection of non-extractable compounds in soil. So-called 'bound residues' consist of a soil component, e.g. humic acids, and an irreversibly bound pollutant. Because of the complexity of those macromolecules conventional analytical methods in general do not work. Enzyme immunoassays, in contrast, seem to have a large potential for applications and further developments in this field. The use of antibodies with high affinity to the analytes makes a selective detection of environmental pollutants possible. With the development of an enzyme-labeled sandwich-immunoassay polycyclic aromatic hydrocarbons (PAHs), irreversibly bound to humic acids, were determined for the first time.

  11. Performance evaluation of two immunoassays for 25-hydroxyvitamin D

    PubMed Central

    Li, Lusha; Zeng, Qin; Yuan, Jingjing; Xie, Zhongjian

    2016-01-01

    Although immunoassays in measuring 25-hydroxyvitamin D [25(OH)D] have been improved recently, relatively large differences are still seen between results of 25(OH)D measured by immunoassays and by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the present studies, we compared two immunoassays with LC-MS/MS for measuring 25(OH)D concentrations. Concentrations of 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] in serum samples from 59 healthy subjects were measured by two immunoassays including Siemens ADVIA Centaur Vitamin D Total (Centaur) and Roche Elecsys Vitamin D Total (Elecsys) and LC-MS/MS. To determine the cross reactivity of Elecsys and Centaur toward 25(OH)D2, a dosage of 200,000 IU vitamin D2 was given after first sampling. Serum samples were obtained 30 days later and concentrations of 25(OH)D2 and 25(OH)D3 were measured again. The results showed poor agreement between the immunoassays and LC-MS/MS in 25(OH)D2 and 25(OH)D3 measurements. The percentage of 25(OH)D2 cross-reactivity was 45.3% for Centaur and 41.2% for Elecsys and there was no significant difference between Centaur and Elecsys. In conclusion, Centaur and Elecsys perform unsatisfactorily in measuring 25(OH)D levels, especially for 25(OH)D2 cross-reactivity. Therefore, clinicians need to be aware of the underestimation of vitamin D status when using these immunoassays for measuring individuals supplemented with vitamin D2. PMID:27257343

  12. Donor Preferences and Charitable Giving

    ERIC Educational Resources Information Center

    Williams, Stephanie Roderick

    2007-01-01

    This study aimed to learn more of the differences that may exist between the two most powerful groups of donors today, baby boomers (40-58 years old) and mature donors (59 and older), in an effort to help organizations improve fundraising efforts. Questions about the importance of organizational efficiency, program outcomes, and the desire for…

  13. Trends in Transfusion Transmitted Infections Among Replacement Blood Donors in Karachi, Pakistan

    PubMed Central

    Irfan, Syed Mohammad; Uddin, Jamal; Zaheer, Hasan Abbas; Sultan, Sadia; Baig, Amjad

    2013-01-01

    Objective: To determine the prevalence of Hepatitis-B, Hepatitis-C and Human Immunodeficiency infections in replacement blood donors. Materials and Methods: From January 2004 to December 2011, 108,598 apparently healthy donors donated blood at our Blood Bank. Screening was done by Microparticle Enzyme Immuno Assay (MEIA) method on Axsym System (Abbott Diagnostic, USA) and in year 2011 by Chemiluminescent Immunoassay (CIA) method on Architect i2000 (Abbott Diagnostic, USA). From 2010 onward, HIV reactive donors were advised for confirmatory tests and reported back with the results. Results: Of the 108,598 total donors, 108,393 (99.8%) were replacement donors with a mean age of 28.92 (17-55) years. Of this, only 164 (0.15%) were females. Among the replacement donors, 4,906 (4.5%) were found to be reactive for Hepatitis-B, C and Human Immunodeficiency Virus. All the reactive patients, except one, were males. HbsAg was positive in 2,068 (1.90%) and anti-HCV in 2832 (2.61%) donors, while 111 (0.10%) were positive for Human Immunodeficiency Virus. Co-infectivity was observed in 103 (0.09%) cases. The prevalence appeared to be higher in younger age group (17-30 yrs). Only 16.6% cases should be patients returned with results of the confirmatory tests for HIV and were found positive. Conclusion: Hepatitis-B and C sero-prevalence in our series of replacement donors appears high compared to most studies from neighboring countries and relatively low in comparison to earlier studies from Pakistan. Prevalence of HIV, however, appears low and turn out of HIV positive cases for confirmatory tests is low. Conflict of interest:None declared. PMID:24385780

  14. Ability of TESTPACK ROTAVIRUS enzyme immunoassay to diagnose rotavirus gastroenteritis.

    PubMed Central

    Chernesky, M; Castriciano, S; Mahony, J; Spiewak, M; Schaefer, L

    1988-01-01

    TESTPACK ROTAVIRUS, a simple 10-min enzyme immunoassay, was compared with electron microscopy and Pathfinder enzyme immunoassay on feces from 172 patients of various ages with gastroenteritis. The percent sensitivities and specificities before blocking with antiserum were as follows: TESTPACK, 100% sensitivity and 99% specificity; Pathfinder, 95% sensitivity and 98% specificity. After blocking, the sensitivity and specificity, respectively, were 100% and 100% for TESTPACK and 95% and 99% for Pathfinder. TESTPACK ROTAVIRUS was more sensitive, but not significantly, than Pathfinder (P greater than 0.1) and the direct electron microscopy technique (P greater than 0.1). PMID:3069866

  15. Robust detection of peak signals for lateral flow immunoassays

    NASA Astrophysics Data System (ADS)

    Kim, Jongwon; Kim, Jong Dae; Nahm, Kie Bong; Choi, Eui Yul; Lee, Geumyoung

    2011-02-01

    Template matching method is presented to identify the peaks from the scanned signals of lateral flow immunoassay strips. The template is composed of two pulses separated by the distance of the control and the target ligand line in the assay, and is convolved with the scanned signal to deliver the maximum at the center of the two peaks. The peak regions were identified with the predefined distances from the center. Glycosylated haemoglobin immunoassay strips and fluorescent strip readers from Boditechmed Inc. were tested to estimate the lot and reader variations of the concentration measurands. The results showed the robustness of the propose method.

  16. Hepatitis B escape mutants in Scottish blood donors.

    PubMed

    Larralde, Osmany; Dow, Brian; Jarvis, Lisa; Davidson, Fiona; Petrik, Juraj

    2013-06-01

    Hepatitis B virus (HBV) remains as the viral infection with the highest risk of transmission by transfusion. This risk is associated with window period donations, occult HBV infection (OBI) and the emergence of escape mutants, which render blood donations false negative for hepatitis B surface antigen (HBsAg) serological testing. A retrospective study was conducted to gain insights into the molecular epidemiology of HBV escape mutants in Scottish blood donors. The criterion for selection was HBV positivity either by serology or nucleic acid testing (NAT). HBsAg detection was compared across several commercial immunoassays. The full length S gene from plasma samples was PCR amplified, cloned and expressed in HepG2 cells. Eight samples showed HBsAg discordant results, while 5 OBI samples were found. Four escape mutants, containing missense mutations in the S gene, are described here. These mutations impaired HBsAg detection both from HBV infected plasma samples and from recombinant proteins derived from its infected donors. Phylogenetic analysis showed that most of the mutants were clustered in the genotype D and were closely related to strains from Asia and the Middle East. We report here a proline substitution, outside the major hydrophilic region, that impaired HBsAg detection in vivo and in vitro, warning about the risk for the emergence of vaccine escape mutants with mutations outside the major neutralisation site. PMID:23274404

  17. The Lombardy Rare Donor Programme

    PubMed Central

    Revelli, Nicoletta; Villa, Maria Antonietta; Paccapelo, Cinzia; Manera, Maria Cristina; Rebulla, Paolo; Migliaccio, Anna Rita; Marconi, Maurizio

    2014-01-01

    Background In 2005, the government of Lombardy, an Italian region with an ethnically varied population of approximately 9.8 million inhabitants including 250,000 blood donors, founded the Lombardy Rare Donor Programme, a regional network of 15 blood transfusion departments coordinated by the Immunohaematology Reference Laboratory of the Ca’ Granda Ospedale Maggiore Policlinico in Milan. During 2005 to 2012, Lombardy funded LORD-P with 14.1 million euros. Materials and methods During 2005–2012 the Lombardy Rare Donor Programme members developed a registry of blood donors and a bank of red blood cell units with either rare blood group phenotypes or IgA deficiency. To do this, the Immunohaematology Reference Laboratory performed extensive serological and molecular red blood cell typing in 59,738 group O or A, Rh CCDee, ccdee, ccDEE, ccDee, K− or k− donors aged 18–55 with a record of two or more blood donations, including both Caucasians and ethnic minorities. In parallel, the Immunohaematology Reference Laboratory implemented a 24/7 service of consultation, testing and distribution of rare units for anticipated or emergent transfusion needs in patients developing complex red blood cell alloimmunisation and lacking local compatible red blood cell or showing IgA deficiency. Results Red blood cell typing identified 8,747, 538 and 33 donors rare for a combination of common antigens, negative for high-frequency antigens and with a rare Rh phenotype, respectively. In June 2012, the Lombardy Rare Donor Programme frozen inventory included 1,157 red blood cell units. From March 2010 to June 2012 one IgA-deficient donor was detected among 1,941 screened donors and IgA deficiency was confirmed in four previously identified donors. From 2005 to June 2012, the Immunohaematology Reference Laboratory provided 281 complex red blood cell alloimmunisation consultations and distributed 8,008 Lombardy Rare Donor Programme red blood cell units within and outside the region

  18. [Altruism and the donor].

    PubMed

    Langlois, A

    1991-08-01

    On December 20, 1988, the government of France passed a law to protect people who voluntarily participate in biomedical research. This article makes extensive reference to a major study, titled From Biology to Ethics, by Jean Bernard, a well-respected authority in the field of bioethics. The author looks at models proposed by Bernard, as examples for health volunteers, in particular, the blood donor and the self-experimenter. To set the tone of the article, she recalls the concept of altruism, as first proposed by Auguste Comte, then makes a linkage between his philosophy and Bernard's point of view. By trial and error, in their discussions, various ethics committees and the French State Council have agreed upon what constitutes fair compensation under the law. Unlike their Canadian counterparts, medical researchers in France have free access to volunteers who are not in perfect health--e.g., the elderly, people suffering from kidney deficiency, cirrhosis of the liver, etc.--but these "experimental subjects" receive no monetary compensation. Thus, healthy and less-than-healthy volunteers do not receive equal treatment under the law. This inequity, added to the fear of what amounts to a tax on the human body and the difficulty of ensuring just compensation, is giving rise to a great deal of uncertainty. PMID:1878857

  19. Successful use of the "unacceptable" heart donor.

    PubMed

    Menkis, A H; Novick, R J; Kostuk, W J; Pflugfelder, P W; Powell, A M; Thomson, D; McKenzie, F N

    1991-01-01

    Chronic shortage of donor organs has heightened interest in new strategies for increasing donor availability. Unacceptable hearts for transplant have previously been characterized by donor age greater than 40 years, more than 20% donor/recipient weight mismatch, ischemic time more than 4 hours, and the presence of coronary artery disease. A series of 185 consecutive orthotopic heart transplants were retrospectively examined. A significant number of donor hearts used were unacceptable by one or more of the above criteria. Our current approach is to match donors to recipients using a wide range of criteria. Donors are now accepted from any location in North America. We have accepted donors more than 55 years of age and donors weighing less than 50% of the recipient's body weight. Because of the chronic shortage of donor organs, donor criteria have been effectively liberalized, thereby increasing the donor pool without compromising the overall results of heart transplantation. PMID:2007168

  20. Thermal cracking with hydrogen donor diluent

    SciTech Connect

    Derbyshire, F.; Varghese, P.; Whitehurst, D.D.

    1983-07-26

    An improved hydrogen donor for hydrogen donor diluent cracking is provided by extraction with naphtha from the cracked product and hydrogenation by hydrogen transfer from a lower boiling hydrogen donor such as tetralin.

  1. Seroepidemiology of infection with Toxoplasma gondii in healthy blood donors of Durango, Mexico

    PubMed Central

    Alvarado-Esquivel, Cosme; Mercado-Suarez, Miguel Francisco; Rodríguez-Briones, Alfredo; Fallad-Torres, Laura; Ayala-Ayala, Julio Octavio; Nevarez-Piedra, Luis Jorge; Duran-Morales, Ehecatl; Estrada-Martínez, Sergio; Liesenfeld, Oliver; Márquez-Conde, José Ángel; Martínez-García, Sergio Arturo

    2007-01-01

    Background Toxoplasma gondii (T. gondii) infection in blood donors could represent a risk for transmission in blood recipients. There is scarce information about the epidemiology of T. gondii infection in blood donors in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic and behavioral characteristics in a population of healthy blood donors of Durango City, Mexico. Methods Four hundred and thirty two blood donors in two public blood banks of Durango City, Mexico were examined for T. gondii infection between August to September 2006. Blood donors were tested for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays (Diagnostic Automation Inc., Calabasas, CA, USA). Socio-demographic and behavioral characteristics from each participant were also obtained. Results Thirty two (7.4%) of 432 blood donors had IgG anti-T. gondii antibodies. Eight (1.9%) of them had also IgM anti-T. gondii antibodies. Multivariate analysis using logic regression showed that T. gondii infection was associated with the presence of cats at home (adjusted OR = 3.81; 95% CI: 1.45–10.01). The age group of 45–60 years showed a significantly higher frequency of T. gondii infection than the group of 25–34 years (p = 0.02). Blood donors without education had a significantly higher frequency of infection (15.8%) than those with 13–19 years of education (4.5%) (p = 0.04). Other characteristics of blood donors including male gender, consumption of undercooked meat or blood transfusion did not show an association with infection. Conclusion The prevalence of T. gondii infection in healthy blood donors of Durango City, Mexico is lower than those reported in blood donors of south and central Mexico, and is one of the lowest reported in blood donors worldwide. T. gondii infection in our blood donors was most likely acquired by contact with cats. Prevalence of infection increased with age and decreased with educational

  2. Adult living donor liver imaging

    PubMed Central

    Cai, Larry; Yeh, Benjamin M.; Westphalen, Antonio C.; Roberts, John P.; Wang, Zhen J.

    2016-01-01

    Adult living donor liver transplantation (LDLT) is increasingly used for the treatment of end-stage liver disease. The three most commonly harvested grafts for LDLT are left lateral segment, left lobe, and right lobe grafts. The left lateral segment graft, which includes Couinaud’s segments II and III, is usually used for pediatric recipients or small size recipients. Most of the adult recipients need either a left or a right lobe graft. Whether a left or right lobe graft should be harvested from the donors depends on estimated graft and donor remnant liver volume, as well as biliary and vascular anatomy. Detailed preoperative assessment of the potential donor liver volumetrics, biliary and vascular anatomy, and liver parenchyma is vital to minimize risks to the donors and maximize benefits to the recipients. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in the preoperative evaluation of potential donors. This review provides an overview of key surgical considerations in LDLT that the radiologists must be aware of, and imaging findings on CT and MRI that the radiologists must convey to the surgeons when evaluating potential donors for LDLT. PMID:26912106

  3. Adult living donor liver imaging.

    PubMed

    Cai, Larry; Yeh, Benjamin M; Westphalen, Antonio C; Roberts, John P; Wang, Zhen J

    2016-01-01

    Adult living donor liver transplantation (LDLT) is increasingly used for the treatment of end-stage liver disease. The three most commonly harvested grafts for LDLT are left lateral segment, left lobe, and right lobe grafts. The left lateral segment graft, which includes Couinaud's segments II and III, is usually used for pediatric recipients or small size recipients. Most of the adult recipients need either a left or a right lobe graft. Whether a left or right lobe graft should be harvested from the donors depends on estimated graft and donor remnant liver volume, as well as biliary and vascular anatomy. Detailed preoperative assessment of the potential donor liver volumetrics, biliary and vascular anatomy, and liver parenchyma is vital to minimize risks to the donors and maximize benefits to the recipients. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in the preoperative evaluation of potential donors. This review provides an overview of key surgical considerations in LDLT that the radiologists must be aware of, and imaging findings on CT and MRI that the radiologists must convey to the surgeons when evaluating potential donors for LDLT. PMID:26912106

  4. Living kidney donors and ESRD.

    PubMed

    Ross, Lainie Friedman

    2015-07-01

    There are more than 325 living kidney donors who have developed end-stage renal disease and have been listed on the Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) deceased donor kidney wait list. The OPTN/UNOS database records where these kidney donors are listed and, if they donated after April 1994, where that donation occurred. These 2 locations are often not the same. In this commentary, I examine whether a national living donor registry should be created and whether transplantation centers should be notified when one of their living kidney donors develops end-stage renal disease. I consider and refute 5 potential objections to center notification. I explain that transplantation centers should look back at these cases and input data into a registry to attempt to identify patterns that could improve donor evaluation protocols. Creating a registry and mining the information it contains is, in my view, our moral and professional responsibility to future patients and the transplantation endeavor. As individuals and as a community, we need to acknowledge the many unknown risks of living kidney donation and take responsibility for identifying these risks. We then must share information about these risks, educate prospective donors about them, and attempt to minimize them. PMID:25936672

  5. Monitoring Pesticides and Personal Care Chemicals in Water by Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the increasing number and quantity of organic pollutants, regulatory authorities require implementation of rapid, reliable, and cost-effective technologies for monitoring of water quality. Immunoassays provide a simple, powerful and inexpensive method for monitoring organic contaminants in bo...

  6. Digital microfluidic magnetic separation for particle-based immunoassays.

    PubMed

    Ng, Alphonsus H C; Choi, Kihwan; Luoma, Robert P; Robinson, John M; Wheeler, Aaron R

    2012-10-16

    We introduce a new format for particle-based immunoassays relying on digital microfluidics (DMF) and magnetic forces to separate and resuspend antibody-coated paramagnetic particles. In DMF, fluids are electrostatically controlled as discrete droplets (picoliters to microliters) on an array of insulated electrodes. By applying appropriate sequences of potentials to these electrodes, multiple droplets can be manipulated simultaneously and various droplet operations can be achieved using the same device design. This flexibility makes DMF well-suited for applications that require complex, multistep protocols such as immunoassays. Here, we report the first particle-based immunoassay on DMF without the aid of oil carrier fluid to enable droplet movement (i.e., droplets are surrounded by air instead of oil). This new format allowed the realization of a novel on-chip particle separation and resuspension method capable of removing greater than 90% of unbound reagents in one step. Using this technique, we developed methods for noncompetitive and competitive immunoassays, using thyroid stimulating hormone (TSH) and 17β-estradiol (E2) as model analytes, respectively. We show that, compared to conventional methods, the new DMF approach reported here reduced reagent volumes and analysis time by 100-fold and 10-fold, respectively, while retaining a level of analytical performance required for clinical screening. Thus, we propose that the new technique has great potential for eventual use in a fast, low-waste, and inexpensive instrument for the quantitative analysis of proteins and small molecules in low sample volumes. PMID:23013543

  7. DETECTION OF NORWALK VIRUS IN STOOLS BY ENZYME IMMUNOASSAY

    EPA Science Inventory

    The development of a solid-phase microtiter enzyme immunoassay (EIA) for detection of Norwalk virus antigen in stool samples is described. The EIA was compared with a previously developed radioimmunoassay (RIA) for detection of Norwalk virus antigen in stools obtained from 30 vol...

  8. Kinase Activity Studied in Living Cells Using an Immunoassay

    ERIC Educational Resources Information Center

    Bavec, Aljos?a

    2014-01-01

    This laboratory exercise demonstrates the use of an immunoassay for studying kinase enzyme activity in living cells. The advantage over the classical method, in which students have to isolate the enzyme from cell material and measure its activity in vitro, is that enzyme activity is modulated and measured in living cells, providing a more…

  9. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

    Callstrom, Matthew R.; Bednarski, Mark D.; Gruber, Patrick R.

    1997-01-01

    An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups.

  10. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

    Callstrom, M.R.; Bednarski, M.D.; Gruber, P.R.

    1997-11-25

    An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups. 19 figs.

  11. Magnetic Beads-based Bioelectrochemical Immunoassay of Polycyclic Aromatic Hydrocarbons

    SciTech Connect

    Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe

    2007-07-01

    A simple, rapid, and sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) has been developed to detect polycyclic aromatic hydrocarbons (PAHs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PAH-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PAH (HRP-PAH). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreaction among PAH-antibody-coated MBs, PAH analyte, and HRP-PAH. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing 3, 3´, 5, 5´- tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) for electrochemical detection. The voltammetric characteristics of the substrate were investigated, and the reduction peak current of TMB was used to quantify the concentration of PAH. The different parameters, including the amount of HRP-PAH conjugates, the enzyme catalytic reaction time, and the pH of the supporting electrolyte that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 50 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical magnetic immunoassay was successfully evaluated with tap water spiked with PAHs, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.

  12. A Compact Immunoassay Platform Based on a Multicapillary Glass Plate

    PubMed Central

    Xue, Shuhua; Zeng, Hulie; Yang, Jianmin; Nakajima, Hizuru; Uchiyama, Katsumi

    2014-01-01

    A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased and the reaction efficiency to be increased. To confirm the concept of the method, human immunoglobulin A (h-IgA) was measured using both the proposed immunoassay system and the traditional 96-well plate method. The proposed method resulted in a 1/5-fold decrease of immunoassay time, and a 1/56-fold cut in reagent consumption with a 0.05 ng/mL of limit of detection (LOD) for IgA. The method was also applied to saliva samples obtained from healthy volunteers. The results correlated well to those obtained by the 96-well plate method. The method has the potential for use in disease diagnostic or on-site immunoassays. PMID:24859022

  13. How to Motivate Whole Blood Donors to Become Plasma Donors

    PubMed Central

    2014-01-01

    This study tested the efficacy of interventions to recruit new plasma donors among whole blood donors. A sample of 924 donors was randomized to one of three conditions: control; information only by nurse; and information plus self-positive image message by nurse (SPI). Participants in the control condition only received a leaflet describing the plasma donation procedure. In the two experimental conditions the leaflet was explained face-to-face by a nurse. The dependent variables were the proportion of new plasma donors and the number of donations at six months. Overall, 141 (15.3%) new plasma donors were recruited at six months. There were higher proportions of new plasma donors in the two experimental conditions compared to the control condition (P < .001); the two experimental conditions did not differ. Also, compared to the control condition, those in the experimental conditions (all Ps < .001) gave plasma more often (information only by nurse:  d = .26; SPI: d = .32); the SPI intervention significantly outperformed (P < .05) the information only by nurse condition. The results suggest that references to feelings of SPI such as feeling good and being proud and that giving plasma is a rewarding personal experience favor a higher frequency of plasma donation. PMID:25530909

  14. Development of an immunoassay to detect benzene adducts in hemoglobin

    SciTech Connect

    Grassman, J.A.

    1993-01-01

    The purpose of this project was to develop an immunoassay to detect the adducts formed in hemoglobin after exposure to benzene, which is known to cause bone marrow degeneration and acute myelogenous leukemia. The use of benzene-adduct detection as a biological monitoring method would permit measurement of low exposures and exposures sustained weeks earlier. The reactivity of hydroquinone, an important benzene metabolite, with blood proteins and amino acids was investigated in order to decide which antigens and analytes were likely to be suitable for immunoassay development. The second section determined the combination of benzene-metabolite and antigen need to produce an immunoassay with the requisite low detection limit and specificity. The immunoassays with the best performance were tested on hemoglobin from benzene-exposed mice. In vitro studies showed that hydroquinone efficiently formed adducts with erythrocyte membranes and hemoglobin but not with albumin. Adduction efficiency was greater in incubations using purified hemoglobin than whole blood. Cysteine accounted for 15 to 27% of the adducts formed by hydroquinone. The site of the other adducts were not identified although there was evidence that the hemoglobin heme was adducted. Adducts were found on only 1 of the 2 globin chains. Tryptic digestion of the globin failed to associate the adducts with a specific peptide. Antigens made from hydroquinone-adducted hemoglobin but not hydroquinone-adducted cysteines coupled to carrier proteins effectively elicited adduct-specific antibodies. Interference due to reactivity to hemoglobin was controlled by using uniform quantities of hemoglobin in all wells. The mid-range of the best assays were approximately 12 pmoles HQ per well. Antibodies directed toward hemoglobin adducted with the benzene metabolites phenol, catechol and 1,2,4-trihydroxybenzene were also made. The performance of the anti-1,2,4-trihydroxybenzene were suitable for quantitative immunoassays.

  15. Donor states in inverse opals

    NASA Astrophysics Data System (ADS)

    Mahan, G. D.

    2014-09-01

    We calculate the binding energy of an electron bound to a donor in a semiconductor inverse opal. Inverse opals have two kinds of cavities, which we call octahedral and tetrahedral, according to their group symmetry. We put the donor in the center of each of these two cavities and obtain the binding energy. The binding energies become very large when the inverse opal is made from templates with small spheres. For spheres less than 50 nm in diameter, the donor binding can increase to several times its unconfined value. Then electrons become tightly bound to the donor and are unlikely to be thermally activated to the semiconductor conduction band. This conclusion suggests that inverse opals will be poor conductors.

  16. Donor states in inverse opals

    SciTech Connect

    Mahan, G. D.

    2014-09-21

    We calculate the binding energy of an electron bound to a donor in a semiconductor inverse opal. Inverse opals have two kinds of cavities, which we call octahedral and tetrahedral, according to their group symmetry. We put the donor in the center of each of these two cavities and obtain the binding energy. The binding energies become very large when the inverse opal is made from templates with small spheres. For spheres less than 50 nm in diameter, the donor binding can increase to several times its unconfined value. Then electrons become tightly bound to the donor and are unlikely to be thermally activated to the semiconductor conduction band. This conclusion suggests that inverse opals will be poor conductors.

  17. Being a Living Donor: Risks

    MedlinePlus

    ... for blood transfusions side effects associated with allergic reactions to the anesthesia death The best source of information about risks and expected donor outcomes is your transplant team. In addition, it’s important to take an active role in ...

  18. Comparison of Common Immunoassay Kits for Effective Application in Workplace Drug Urinalysis.

    PubMed

    Liu, R H

    1994-06-01

    Workplace drug urinalysis protocols include an initial immunoassay followed by a confirmation gas chromatography/mass spectrometry (GC/MS) test of immunoassay-positive samples. (Drug categories that are commonly tested include: amphetamines, barbiturates, benzodiazepines, cannabis, cocaine, lysergic acid diethyl amide, methadone, methaqualone, opiates, phencyclidine, and propoxyphene. Not all drug categories are tested by all workplace drug urinalysis programs.) Only those samples that are tested positive by both the initial and the confirmatory procedures can be reported as positive. Thus, when adopting an immunoassay, one must have knowledge of the assay's cross-reacting characteristics and the assay's apparent analyze concentration that corresponds to a specific analyze concentration determined by the GC/MS procedure. The underlying principles of the commonly used radioimmunoassay, enzyme immunoassay, fluorescence polarization immunoassay, and particle immunoassay are outlined. Cross-reacting characteristics of these immunoassays as reported by the manufacturers and independent laboratories are tabulated. This information shown that commercial immunoassay kits for drug categories that are included in workplace drug urinalysis programs are generally more specific than those kits that are for clinical use only. Furthermore, recently manufactured immunoassay kits targeted for use in workplace drug urinalysis programs are more specific than those manufactured earlier. Reported effects of adulterants, such as salt, cleaning agents, etc., on commonly used immunoassays are summarized. Without more comprehensive and systematic studies, it is difficult to make general statements concerning the superiority of one methodology over the others. It is clear, however, that cannabinoid assesses are most susceptible to the influence of adulterants. Reported immunoassay-GC/MS correlation data are reviewed. Significant correlations exist in all cases. The immunoassay apparent

  19. General Bioluminescence Resonance Energy Transfer Homogeneous Immunoassay for Small Molecules Based on Quantum Dots.

    PubMed

    Yu, Xuezhi; Wen, Kai; Wang, Zhanhui; Zhang, Xiya; Li, Chenglong; Zhang, Suxia; Shen, Jianzhong

    2016-04-01

    Here, we describe a general bioluminescence resonance energy transfer (BRET) homogeneous immunoassay based on quantum dots (QDs) as the acceptor and Renilla luciferase (Rluc) as the donor (QD-BRET) for the determination of small molecules. The ratio of the donor-acceptor that could produce energy transfer varied in the presence of different concentrations of free enrofloxacin (ENR), an important small molecule in food safety. The calculated Förster distance (R0) was 7.86 nm. Under optimized conditions, the half-maximal inhibitory concentration (IC50) for ENR was less than 1 ng/mL and the linear range covered 4 orders of magnitude (0.023 to 25.60 ng/mL). The cross-reactivities (CRs) of seven representative fluoroquinolones (FQs) were similar to the data obtained by an enzyme-linked immunosorbent assay (ELISA). The average intra- and interassay recoveries from spiked milk of were 79.8-118.0%, and the relative standard deviations (RSDs) were less than 10%, meeting the requirement of residue detection, which was a satisfactory result. Furthermore, we compared the influence of different luciferase substrates on the performance of the assay. Considering sensitivity and stability, coelenterazine-h was the most appropriate substrate. The results from this study will enable better-informed decisions on the choice of Rluc substrate for QD-BRET systems. For the future, the QD-BRET immunosensor could easily be extended to other small molecules and thus represents a versatile strategy in food safety, the environment, clinical diagnosis, and other fields. PMID:26948147

  20. Motivations for Giving of Alumni Donors, Lapsed Donors and Non-Donors: Implications for Christian Higher Education

    ERIC Educational Resources Information Center

    Rugano, Emilio Kariuki

    2011-01-01

    This descriptive and causal comparative study sought to identify motivations for alumni donor acquisition and retention in Christian institutions of higher learning. To meet this objective, motivations for alumni donors, lapsed donors, and non-donors were analyzed and compared. Data was collected through an electronic survey of a stratified sample…

  1. His-tag protein monitoring by a fast mix-and-measure immunoassay

    PubMed Central

    Kreisig, Thomas; Prasse, Agneta A.; Zscharnack, Kristin; Volke, Daniela; Zuchner, Thole

    2014-01-01

    Here, we present a fast mix-and-measure immunoassay for the specific semiquantitative detection of His-tagged proteins, for example in E. coli cell lysate. The assay is based on Förster resonance energy transfer (FRET) between a lanthanide dye-labeled low-affinity His-peptide and an acceptor-labeled anti-His-tag antibody. The targeted His-tag protein in the sample displaces the donor-labeled peptide and leads to a concentration-dependent time-resolved fluorescence signal. The assay has a total assay time of less than two minutes including sample preparation. The assay recognizes both, N- and C-terminally tagged proteins. The detection limit is comparable to those obtained in SDS-PAGE or Western Blot, which are used as standard methods for the characterization of His-tag protein expression. Additionally, we demonstrate a full compatibility of the developed assay to cell lysate, and a correlation to detectable bands in a western blot application. In conclusion, this fast, sensitive, specific and affordable mix-and-measure assay provides a timesaving and user-friendly way to quantify recombinant protein expression. It substantially reduces the workload for recombinant protein detection, especially when His-tag-protein-containing fractions in manual chromatographic purifications have to be identified. PMID:25000910

  2. Introducing novel amorphous carbon nanoparticles as energy acceptors into a chemiluminescence resonance energy transfer immunoassay system.

    PubMed

    Wang, Zhenxing; Gao, Hongfei; Fu, Zhifeng

    2013-11-21

    A novel chemiluminescence resonance energy transfer (CRET) system for competitive immunoassay of biomolecules was developed by using novel amorphous carbon nanoparticles (CNPs) prepared from candle soot as energy acceptors. The CNPs were firstly prepared to bind with the antigen (Ag) for obtaining the nanocomposite CNP-Ag, and this obtained CNP-Ag was then reacted with the horseradish peroxidase-labeled antibody (HRP-Ab) to assemble the CRET system. The luminol catalyzed by HRP serving as the energy donor for CNPs triggered the CRET phenomenon between luminol and CNPs, which led to the chemiluminescence signal decrease. Due to the competitive immunoreaction of the target antigen and the CNP-Ag, a part of the CNP-Ag was replaced from the HRP-Ab, and then resulted in a weaker interaction between luminol and CNPs. Thus the competitive immunoreaction led to a higher chemiluminescence emission. This CNP-based CRET system was successfully applied to detect the human IgG as a model analyte, and a linear range of 10-200 ng mL(-1) and a detection limit of 1.9 ng mL(-1) (S/N = 3) were obtained. The results for real sample analysis demonstrated its application potential in some important areas such as clinical diagnosis. PMID:23979821

  3. Recombinant antigen-based enzyme immunoassay for screening of Treponema pallidum antibodies in blood bank routine.

    PubMed Central

    Zrein, M; Maure, I; Boursier, F; Soufflet, L

    1995-01-01

    This work reports a comparison of an enzyme immunoassay (EIA) using two major Treponema pallidum recombinant antigens with a T. pallidum hemagglutination (TPHA) assay and a nontreponemal Venereal Disease Reference Laboratory (VDRL) test. A total of 1,822 normal donor serum samples was tested for cardiolipin and T. pallidum antibodies, respectively, by the VDRL assay and EIA. Among these samples, 440 were further tested by TPHA technology. Four samples were found positive by EIA, while all were reported to be negative by both TPHA and VDRL routine assays. Subsequent testing of EIA-positive samples confirmed 100% (four of four samples) and 25% (one of four samples) positive results, respectively, by immunofluorescence assay and a Western blot (immunoblot) syphilis kit. The sensitivity of the recombinant EIA was estimated at virtually 100% with a reference panel of 50 syphilitic samples. According to this study, the newly developed EIA kit shows 100% sensitivity combined to a specificity greater than 99.8% for detecting treponemal immunoglobulin G antibodies in blood bank syphilis screening. PMID:7751351

  4. The Bioluminescence Resonance Energy Transfer from Firefly Luciferase to a Synthetic Dye and its Application for the Rapid Homogeneous Immunoassay of Progesterone.

    PubMed

    Smirnova, Daria V; Samsonova, Jeanne V; Ugarova, Natalia N

    2016-01-01

    The sensitive BRET system for the homogeneous immunoassay of a low-molecular weight antigen was developed using progesterone as an example. Two thermostable mutants of the Luciola mingrelica firefly luciferase (Luc)-the "red" mutant with λmax.em = 590 nm (RedLuc) and the "green" mutant with λmax.em = 550 nm (GreenLuc)-were tested as the donors. The water-soluble Alexa Fluor 610× (AF) dye was selected as the acceptor because its two absorption maxima, located at 550 and 610 nm, are close to the bioluminescence maxima of the GreenLuc and RedLuc, respectively. The methods for the synthesis of the luciferase-progesterone (Luc-Pg) conjugate and the conjugate of the dye and the polyclonal antiprogesterone antibody (AF-Ab) were developed. Both conjugates retained their functional properties, had high antigen-antibody binding activity, and demonstrated a high BRET signal. The homogeneous immunoassay system based on the BRET from the firefly luciferase to the synthetic dye was established to assay progesterone as a model antigen. Optimization of the assay conditions, the composition of the reaction mixture, and the concentrations of the donor and the acceptor made it possible to reach the minimum detectable progesterone concentration of 0.5 ng mL(-1) . PMID:26650341

  5. Analysis of Donor Motivations in Living Donor Liver Transplantation

    PubMed Central

    Abdeldayem, Hesham; Kashkoush, Samy; Hegab, Bassem Soliman; Aziz, Amr; Shoreem, Hany; Saleh, Shereef

    2014-01-01

    Objectives: The introduction of the living donor liver transplantation (LDLT) in Egypt as in elsewhere, has raised important psychological conflicts and ethical questions. The objective of this study was to get better understanding of the potential donors’ motives toward LDLT. Methods: This study was conducted on consecutive 193 living-liver donors who underwent partial hepatectomy as donors for LDLT during the period between April 2003 and January 2013, at the National Liver Institute Menoufeyia University, Egypt. Potential donors were thoroughly evaluated preoperatively through a screening questionnaire and interviews as regard their demographic data, relationship to the potential recipient, and motives toward proceeding to surgery. They were assured that the information shared between them and the transplant center is confidential. Results: The donors’ mean age was 25.53 ± 6.39 years with a range of 18–45 years. Males represented 64.7% and females were 35.3%. The most common donors (32.1%, n = 62) were sons and daughters to their parents (sons: n = 43, daughters: n = 19) while parents to their offsprings represent 15% (mothers: n = 21, fathers: n = 8). Brothers and sisters represent 16.5% (brothers: n = 22, sisters: n = 10). Nephews and nieces giving their uncles or aunts were 14%. The number of wives donating to their husbands was 11 (5.7%). Interestingly, there was no single husband who donated his wife. Among the remaining donors, there were 11 cousins and 1 uncle. Unrelated donors were 20 (10.4%). Several factors seemed to contribute to motivation for donation: the seriousness of the potential recipient condition, the relationship and personal history of the donor to the potential recipient, the religious beliefs, the trust in the health care system, and family dynamics and obligations. Conclusion: Absolute absence of coercion on the living-liver donor’s motives may not be realistic because of the serious

  6. Blood Donation by Elderly Repeat Blood Donors

    PubMed Central

    Zeiler, Thomas; Lander-Kox, Jutta; Alt, Timo

    2014-01-01

    Summary Background Upper age limits for blood donors are intended to protect elderly blood donors from donor reactions. However, due to a lack of data about adverse reactions in elderly blood donors, upper age limits are arbitrary and vary considerably between different countries. Methods Here we present data from 171,231 voluntary repeat whole blood donors beyond the age of 68 years. Results Blood donations from repeat blood donors beyond the age of 68 years increased from 2,114 in 2005 to 38,432 in 2012 (from 0,2% to 4.2% of all whole blood donations). Adverse donor reactions in repeat donors decreased with age and were lower than in the whole group (0.26%), even in donors older than 71 years (0.16%). However, from the age of 68 years, the time to complete recovery after donor reactions increased. Donor deferrals were highest in young blood donors (21.4%), but increased again in elderly blood donors beyond 71 years (12.6%). Conclusion Blood donation by regular repeat blood donors older than 71 years may be safely continued. However, due to a lack of data for donors older than 75 years, blood donation in these donors should be handled with great caution. PMID:25254019

  7. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

    NASA Astrophysics Data System (ADS)

    TakYu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

    2015-06-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL-1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications.

  8. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

    PubMed Central

    Tak For Yu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

    2015-01-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL−1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications. PMID:26074253

  9. Donor Hemovigilance with Blood Donation

    PubMed Central

    Diekamp, Ulrich; Gneißl, Johannes; Rabe, Angela; Kießig, Stephan T.

    2015-01-01

    Background Reports on unexpected events (UEs) during blood donation (BD) inadequately consider the role of technical UEs. Methods Defined local and systemic UEs were graded by severity; technical UEs were not graded. On January 1, 2008, E.B.P.S.-Logistics (EBPS) installed the UE module for plasma management software (PMS). Donor room physicians entered UEs daily into PMS. Medical directors reviewed entries quarterly. EBPS compiled data on donors, donations, and UEs from January 1, 2008 to June 30, 2011. Results 6,605 UEs were observed during 166,650 BDs from 57,622 donors for a corrected incidence of 4.30% (0.66% local, 1.59% systemic, 2.04% technical UEs). 2.96% of BDs were accompanied by one UE and 0.45% by >1 UE (2-4). 6.3% of donors donating blood for their first time, 3.5% of those giving blood for their second time, and 1.9% of donors giving their third or more BD experienced UEs. Most common UEs were: discontinued collections due to venous access problems, repeated venipuncture, and small hematomas. Severe circulatory UEs occurred at a rate of 16 per 100,000 BDs. Conclusions Technical UEs were common during BD. UEs accompanied first and second donations significantly more often than subsequent donations. PMID:26195932

  10. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

    PubMed Central

    Noroozi, Zahra; Kido, Horacio; Peytavi, Régis; Nakajima-Sasaki, Rie; Jasinskas, Algimantas; Micic, Miodrag; Felgner, Philip L.; Madou, Marc J.

    2011-01-01

    A novel, centrifugal disk-based micro-total analysis system (μTAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude. PMID:21721711

  11. Fluorescence polarization immunoassays for the quantification of caffeine in beverages.

    PubMed

    Oberleitner, Lidia; Grandke, Julia; Mallwitz, Frank; Resch-Genger, Ute; Garbe, Leif-Alexander; Schneider, Rudolf J

    2014-03-19

    Homogeneous fluorescence polarization immunoassays (FPIAs) were developed and compared for the determination of caffeine in beverages and cosmetics. FPIAs were performed in cuvettes in a spectrometer for kinetic FP measurements as well as in microtiter plates (MTPs) on a multimode reader. Both FPIAs showed measurement ranges in the μg/L range and were performed within 2 and 20 min, respectively. For the application on real samples, high coefficients of variations (CVs) were observed for the performance in MTPs; the CVs for FPIAs in cuvettes were below 4%. The correlations between this method and reference methods were satisfying. The sensitivity was sufficient for all tested samples including decaffeinated coffee without preconcentration steps. The FPIA in cuvettes allows a fast, precise, and automated quantitative analysis of caffeine in consumer products, whereas FPIAs in MTPs are suitable for semiquantitative high-throughput screenings. Moreover, specific quality criteria for heterogeneous assays were applied to homogeneous immunoassays. PMID:24597592

  12. Urinary microalbumin measurement using a homogeneous liposomal immunoassay.

    PubMed

    Frost, S J; Chakraborty, J; Firth, G B

    1996-08-14

    A homogeneous colorimetric immunoassay which has been developed for urinary microalbumin utilizes complement-mediated immunolysis of liposomes containing the dye, sulphorhodamine B. Unlike a previously described model complement-mediated liposomal assay for serum albumin (Frost et al., 1994) which was competitive, this assay uses a sandwich-type format and Fab' (antialbumin)-coated liposomes to increase the assay sensitivity. The liposomal assay, performed using a Cobas Bio analyser (Roche, Welwyn Garden City, UK), gave an acceptable correlation with a radioimmunoassay (NETRIA, London, UK): r = 0.94; y (liposomal assay) = 1.09 x (radioimmunoassay) - 1.54 mg/1. The imprecisions of the assays were similar and matrix effects due to the use of urine samples were determined to be acceptably small. The assay demonstrates the advantage of using Fab'-coated liposomes in sandwich-type liposomal immunoassays over liposomes coated with intact antibody, which failed to elicit complement-mediated immunolysis. PMID:8765163

  13. Design and Fabrication of a PDMS Microchip Based Immunoassay

    SciTech Connect

    Shao, Guocheng; Wang, Wanjun; Wang, Jun; Lin, Yuehe

    2010-07-01

    In this paper, we describe the design and fabrication process of a polydimethylsiloxane (PDMS) microchip for on-chip multiplex immunoassay application. The microchip consists of a PDMS microfluidic channel layer and a micro pneumatic valve control layer. By selectively pressurizing the pneumatic microvalves, immuno reagents were controlled to flow and react in certain fluidic channel sites. Cross contamination was prevented by tightly closed valves. Our design was proposed to utilize PDMS micro channel surface as the solid phase immunoassay substrate and simultaneously detect four targets antigens on chip. Experiment result shows that 20psi valve pressure is sufficient to tightly close a 200µm wide micro channel with flow rate up to 20µl/min.

  14. Silver and gold enhancement methods for lateral flow immunoassays.

    PubMed

    Rodríguez, Myriam Oliveira; Covián, Lucía Blanco; García, Agustín Costa; Blanco-López, Maria Carmen

    2016-02-01

    Sensitivity is the main concern at the development of rapid test by lateral flow immunoassays. On the other hand, low limits of detection are often required at medical diagnostics and other field of analysis. To overcome this drawback, several enhancement protocols have been described. In this paper, we have selected different silver enhancement methods and one dual gold conjugation, and we critically compared the amplification produced when applied to a gold-nanoparticle based lateral flow immunoassay for the detection of prostate specific antigen (PSA). The highest amplification was obtained by using an immersion method based on a solution of silver nitrate and hydroquinone/citrate buffer in proportion 1:1. Under these conditions, the system is capable of detecting PSA within 20 min at levels as low as 0.1 ng/mL, with a 3-fold sensitivity improvement. PMID:26653449

  15. Multiplexed electrochemical immunoassay of biomarkers using chitosan nanocomposites.

    PubMed

    Chen, Xia; Ma, Zhanfang

    2014-05-15

    In this work, a novel and sensitive multiplexed immunoassay protocol for simultaneous electrochemical determination of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) was designed using functionalized chitosan composites. The immunosensing platform was prepared via immobilizing capture anti-AFP and anti-CEA on chitosan-Au nanoparticles (AuNPs) through EDC/NHS linking. The signal tags were fabricated by immobilizing electroactive redox probes - Prussian blue (PB) and ferrocenecarboxylic acid (Fc) on chitosan (CHIT), following by absorbing AuNPs to immobilize labeled anti-AFP and anti-CEA, respectively. A sandwich-type immunoassay format was employed for the simultaneous detection of AFP and CEA. The assay was based on the electrochemical oxidation/reduction of the redox species in signal tags, which has a relationship with the concentration of analytes. Experimental results revealed that the multiplexed electrochemical immunoassay enabled the simultaneous monitoring of AFP and CEA with a wide range of 0.05-100 ng mL(-1) for both AFP and CEA. The detection limits (LOD) was 0.03 ng mL(-1) for AFP and 0.02 ng mL(-1) for CEA (S/N=3). The assay results of serum samples with the proposed method were in a good agreement with the reference values from standard ELISA method. And the negligible cross-reactivity between the two analytes makes it possesses potential promise in clinical diagnosis. PMID:24413402

  16. Specific Noncompetitive Immunoassay for HT-2 Mycotoxin Detection.

    PubMed

    Arola, Henri O; Tullila, Antti; Kiljunen, Harri; Campbell, Katrina; Siitari, Harri; Nevanen, Tarja K

    2016-02-16

    Here we demonstrate a novel homogeneous one-step immunoassay, utilizing a pair of recombinant antibody antigen-binding fragments (Fab), that is specific for HT-2 toxin and has a positive readout. Advantages over the conventional competitive immunoassay formats such as enzyme-linked immunosorbent assay (ELISA) are the specificity, speed, and simplicity of the assay. Recombinant antibody HT2-10 Fab recognizing both HT-2 and T-2 toxins was developed from a phage display antibody library containing 6 × 10(7) different antibody clones. Specificity of the immunoassay was introduced by an anti-immune complex (IC) antibody binding the primary antibody-HT-2 toxin complex. When the noncompetitive immune complex assay was compared to the traditional competitive assay, an over 10-fold improvement in sensitivity was observed. Although the HT2-10 antibody has 100% cross-reactivity for HT-2 and T-2 toxins, the immune complex assay is highly specific for HT-2 alone. The assay performance with real samples was evaluated using naturally contaminated wheat reference material. The half-maximal effective concentration (EC50) value of the time-resolved fluorescence resonance energy transfer (TR-FRET) assay was 9.6 ng/mL, and the limit of detection (LOD) was 0.38 ng/mL (19 μg/kg). The labeled antibodies can be predried to the assay vials, e.g., microtiter plate wells, and readout is ready in 10 min after the sample application. PMID:26785138

  17. An embedded microretroreflector-based microfluidic immunoassay platform.

    PubMed

    Raja, Balakrishnan; Pascente, Carmen; Knoop, Jennifer; Shakarisaz, David; Sherlock, Tim; Kemper, Steven; Kourentzi, Katerina; Renzi, Ronald F; Hatch, Anson V; Olano, Juan; Peng, Bi-Hung; Ruchhoeft, Paul; Willson, Richard

    2016-04-26

    We present a microfluidic immunoassay platform based on the use of linear microretroreflectors embedded in a transparent polymer layer as an optical sensing surface, and micron-sized magnetic particles as light-blocking labels. Retroreflectors return light directly to its source and are highly detectable using inexpensive optics. The analyte is immuno-magnetically pre-concentrated from a sample and then captured on an antibody-modified microfluidic substrate comprised of embedded microretroreflectors, thereby blocking reflected light. Fluidic force discrimination is used to increase specificity of the assay, following which a difference imaging algorithm that can see single 3 μm magnetic particles without optical calibration is used to detect and quantify signal intensity from each sub-array of retroreflectors. We demonstrate the utility of embedded microretroreflectors as a new sensing modality through a proof-of-concept immunoassay for a small, obligate intracellular bacterial pathogen, Rickettsia conorii, the causative agent of Mediterranean Spotted Fever. The combination of large sensing area, optimized surface chemistry and microfluidic protocols, automated image capture and analysis, and high sensitivity of the difference imaging results in a sensitive immunoassay with a limit of detection of roughly 4000 R. conorii per mL. PMID:27025227

  18. Multiplex Electrochemical Immunoassay Using Gold Nanoparticle Probes and Immunochromatographic Strips

    SciTech Connect

    Mao, Xun; Baloda, Meenu; Gurung, Anant; Lin, Yuehe; Liu, Guodong

    2008-10-20

    We describe a multiplex electrochemical immunoassay based on the use of gold nanoparticle (Au-NP) probes and immunochromatographic strips (ISs). The approach takes advantage of the speed and low cost of the conventional IS tests and the high sensitivities of the nanoparticle-based electrochemical immunoassays. Rabbit IgG(R-IgG) and human IgM (H-IgM) were used as model targets for the demonstration of the proof of concept. The Au-NPs based sandwich immunoreactions were performed on the IS, and the captured gold nanoparticle labels on the test zones were determined by highly-sensitive stripping voltammetric measurement of the dissolved gold ions (III) with a carbon paste electrode. The detection limits are 1.0 and 1.5 ng/mL with the linear ranges of 2.5-250 ng/mL for quantitative detection of R-IgG and H-IgM, respectively. The total assay time is around 25 minutes. Such multiplex electrochemical immunoassay could be readily highly multiplexed to allow simultaneous parallel detection of numerous proteins and is expected to open new opportunities for protein diagnostics and biosecurity.

  19. [Living donor transplantation. Surgical complications].

    PubMed

    Karam, Georges

    2008-02-01

    Although nephrectomy by open surgery is the most used technique for the extraction of kidney transplants in the living donor, nephrectomy under laparaoscopy is increasingly practiced. Laparoscopic nephrectomy is less invasive and performed under videoscopy control, after insufflation of the peritoneal cavity. Three to four incisions are done in order to enter the surgical instruments. The kidney is extracted through a horizontal sus-pubic incision. The exposition is either exclusively transperitoneal, retroperitoneal or hand assisted. The advantages of laparoscopy are esthetical, financial due to a shorter hospitalisation and a quicker recovery, as well a confort for the donor. The disadvantages are a longer warm ischemia time and possibly a higher risk of delayed graft function. Randomised studies having compared laparoscopy and open surgery in the living donor have not find any significant difference regarding the per- and perioperative in the complications. PMID:18160357

  20. Benzene-RISc: The development and performance of an immunoassay to detect benzene in water

    SciTech Connect

    Friedman, S.B.; Withers, T.; Almond, R.; Stewart, T.; Allen, R.L.

    1994-12-31

    Immunoassay methods have become available for environmental applications. Their simplicity, reliability, and ability to provide information rapidly and on-site is enhancing the efficiency of many field and laboratory programs. Immunoassay methods rely upon antibody molecules to provide the sensitivity and specificity characteristics they exhibit, but many molecules are either insufficiently immunogenic or structurally unremarkable to induce an appropriate antibody response. Such compounds are usually considered to be incompatible with the development of an immunoassay method. An immunoassay method for the detection of benzene in water would have utility in detecting contamination from spills and leaking underground storage tanks. Benzene, however, is frequently considered to be in the class of compounds considered to be incompatible with antibody, and therefore immunoassay, development. The authors have developed an immunoassay for the detection of benzene in water by developing both sample processing and immunochemical procedures and reagents that overcome the technical limitations frequently encountered.

  1. [Prevalence for seropositivity for HIV, hepatitis B and hepatitis C in blood donors].

    PubMed

    Rivera-López, María Rebeca F; Zavala-Méndez, Celia; Arenas-Esqueda, Alfonso

    2004-01-01

    Despite utilizing different actions to render blood safe for transfusions, we continue to have the risk of transmitting some viral infections. For this reason, it is important to determine prevalence of infections due to HIV and hepatitis B and hepatitis C viruses in blood donors. Previous studies from Mexico indicate that HIV prevalence is 0.01 to 0.13%, while it is 0.11 to 1.22% for hepatitis B, and for hepatitis C, prevalence is 0.47 to 1.47%. We are checking the results of the screening tests (ELISA 3rd generation and chemiluminescent immunoassays) from blood donors studied at the Central Blood Bank (Banco Central de Sangre) at the Mexican Institute of Social Security's (IMSS) Twentieth First Century National Medical Center in Mexico City from 1995 to 2002. Reactive results were studied by confirmatory tests, Western Blot for HIV, AgHBs neutralization test for hepatitis B, and RIBA-HCV3.0 for hepatitis C. Reactive results from 513,062 blood donors confirmed for HV were 0.07%, reactive results and confirmation of hepatitis B from 511,733 blood donors were 0.13%, and reactive results and confirmation of hepatitis C from 511,115 blood donors were 0.31%. Rates obtained are low when compared with results of previous studies in Mexico for HIV, hepatitis B, and hepatitis C. It may be possible than these low rates indicate the positive impact obtained from preventive actions, better strategies of detection of blood donors with high risk, and the advantage of working with a fully automated test system with state-of-the-art technology. PMID:15633577

  2. Utilization of Deceased Donor Kidneys to Initiate Living Donor Chains.

    PubMed

    Melcher, M L; Roberts, J P; Leichtman, A B; Roth, A E; Rees, M A

    2016-05-01

    We propose that some deceased donor (DD) kidneys be allocated to initiate nonsimultaneous extended altruistic donor chains of living donor (LD) kidney transplants to address, in part, the huge disparity between patients on the DD kidney waitlist and available donors. The use of DD kidneys for this purpose would benefit waitlisted candidates in that most patients enrolled in kidney paired donation (KPD) systems are also waitlisted for a DD kidney transplant, and receiving a kidney through the mechanism of KPD will decrease pressure on the DD pool. In addition, a LD kidney usually provides survival potential equal or superior to that of DD kidneys. If KPD chains that are initiated by a DD can end in a donation of an LD kidney to a candidate on the DD waitlist, the quality of the kidney allocated to a waitlisted patient is likely to be improved. We hypothesize that a pilot program would show a positive impact on patients of all ethnicities and blood types. PMID:26833680

  3. Documented deaths of hepatic lobe donors for living donor liver transplantation.

    PubMed

    Trotter, James F; Adam, Rene; Lo, Chung Mau; Kenison, Jeremy

    2006-10-01

    The actual risk of death in hepatic lobe donors for living donor liver transplantation (LDLT) is unknown because of the lack of a comprehensive database. In the absence of a definitive estimate of the risk of donor death, the medical literature has become replete with anecdotal reports of donor deaths, many of which cannot be substantiated. Because donor death is one of the most important outcomes of LDLT, we performed a comprehensive survey of the medical and lay literature to provide a referenced source of worldwide donor deaths. We reviewed all published articles from the medical literature on LDLT and searched the lay literature for donor deaths from 1989 to February 2006. We classified each death as "definitely," "possibly," or "unlikely" related to donor surgery. We identified 19 donor deaths (and one additional donor in a chronic vegetative state). Thirteen deaths and the vegetative donor were "definitely," 2 were "possibly," and 4 were "unlikely" related to donor surgery. The estimated rate of donor death "definitely" related to donor surgery is 0.15%. The rate of donor death which is "definitely" or "possibly" related to the donor surgery is 0.20%. This analysis provides a source document of all identifiable living liver donor deaths, provides a better estimate of donor death rate, and may provide an impetus for centers with unreported deaths to submit these outcomes to the liver transplantation community. PMID:16952175

  4. Single-Donor Leukophoretic Technique

    NASA Technical Reports Server (NTRS)

    Eberhardt, R. N.

    1977-01-01

    Leukocyte separation-and-retrieval device utilizes granulocyte and monocyte property of leukoadhesion to glass surfaces as basis of their separation from whole blood. Device is used with single donor technique and has application in biological and chemical processing, veterinary research and clinical care.

  5. Physician Migration: Donor Country Impact

    ERIC Educational Resources Information Center

    Aluwihare, A. P. R.

    2005-01-01

    Physician migration from the developing to developed region of a country or the world occurs for reasons of financial, social, and job satisfaction. It is an old phenomenon that produces many disadvantages for the donor region or nation. The difficulties include inequities with the provision of health services, financial loss, loss of educated…

  6. Enantioselective Intramolecular C-H Insertion of Donor and Donor/Donor Carbenes by a Nondiazo Approach.

    PubMed

    Zhu, Dong; Ma, Jun; Luo, Kui; Fu, Hongguang; Zhang, Li; Zhu, Shifa

    2016-07-11

    The first enantioselective intramolecular C-H insertion and cyclopropanation reactions of donor- and donor/donor-carbenes by a nondiazo approach are reported. The reactions were conducted in a one-pot manner without slow addition and provided the desired dihydroindole, dihydrobenzofuran, tetrahydrofuran, and tetrahydropyrrole derivatives with up to 99 % ee and 100 % atom efficiency. PMID:27265896

  7. Micromotor-based lab-on-chip immunoassays

    NASA Astrophysics Data System (ADS)

    García, Miguel; Orozco, Jahir; Guix, Maria; Gao, Wei; Sattayasamitsathit, Sirilak; Escarpa, Alberto; Merkoçi, Arben; Wang, Joseph

    2013-01-01

    Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic polymer/Ni/Pt microtube engine, containing carboxy moieties on its mixed poly(3,4-ethylenedioxythiophene) (PEDOT)/COOH-PEDOT polymeric outermost layer, is further functionalized with the antibody receptor to selectively recognize and capture the target protein. The new motor-based microchip immunoassay operations are carried out without any bulk fluid flow, replacing the common washing steps in antibody-based protein bioassays with the active transport of the captured protein throughout the different reservoirs, where each step of the immunoassay takes place. A first microchip format involving an `on-the-fly' double-antibody sandwich assay (DASA) is used for demonstrating the selective capture of the target protein, in the presence of excess of non-target proteins. A secondary antibody tagged with a polymeric-sphere tracer allows the direct visualization of the binding events. In a second approach the immuno-nanomotor captures and transports the microsphere-tagged antigen through a microchannel network. An anti-protein-A modified microengine is finally used to demonstrate the selective capture, transport and convenient label-free optical detection of a Staphylococcus aureus target bacteria (containing proteinA in its cell wall) in the presence of a large excess of non-target (Saccharomyces cerevisiae) cells. The resulting nanomotor-based microchip immunoassay offers considerable potential for diverse applications in clinical diagnostics, environmental and security monitoring fields.Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic

  8. Compact quantum dot-antibody conjugates for FRET immunoassays with subnanomolar detection limits

    NASA Astrophysics Data System (ADS)

    Mattera, Lucia; Bhuckory, Shashi; Wegner, K. David; Qiu, Xue; Agnese, Fabio; Lincheneau, Christophe; Senden, Tim; Djurado, David; Charbonnière, Loïc J.; Hildebrandt, Niko; Reiss, Peter

    2016-05-01

    A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields ultra-compact, stable, and highly luminescent antibody-QD conjugates suitable for use in FRET immunoassays. Hydrophobic InPZnS/ZnSe/ZnS (emission wavelength: 530 nm), CdSe/ZnS (605 nm), and CdSeTe/ZnS (705 nm) QDs were surface functionalized with zwitterionic penicillamine, enabling aqueous phase transfer under conservation of the photoluminescence properties. Post-functionalization with a heterobifunctional crosslinker, containing a lipoic acid group and a maleimide function, enabled the subsequent coupling to sulfhydryl groups of proteins. This was demonstrated by QD conjugation with fragmented antibodies (F(ab)). The obtained F(ab)-QD conjugates range among the smallest antibody-functionalized nanoprobes ever reported, with a hydrodynamic diameter <13 nm, PL quantum yield up to 66% at 705 nm, and colloidal stability of several months in various buffers. They were applied as FRET acceptors in homogeneous, time-gated immunoassays using Tb-antibodies as FRET donors, both coupled by an immunological sandwich complex between the two antibodies and a PSA (prostate specific antigen) biomarker. The advantages of the compact surface coating for FRET could be demonstrated by an 6.2 and 2.5 fold improvement of the limit of detection (LOD) for PSA compared to commercially available hydrophilic QDs emitting at 605 and 705 nm, respectively. While the commercial QDs contain identical inorganic cores responsible for their fluorescence, they are coated with a comparably thick amphiphilic polymer layer leading to much larger hydrodynamic diameters (>26 nm without biomolecules). The LODs of 0.8 and 3.7 ng mL-1 obtained in 50 μL serum samples are below the clinical cut-off level of PSA (4 ng mL-1) and demonstrate their direct applicability in clinical diagnostics.A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields

  9. Compact quantum dot-antibody conjugates for FRET immunoassays with subnanomolar detection limits

    NASA Astrophysics Data System (ADS)

    Mattera, Lucia; Bhuckory, Shashi; Wegner, K. David; Qiu, Xue; Agnese, Fabio; Lincheneau, Christophe; Senden, Tim; Djurado, David; Charbonnière, Loïc J.; Hildebrandt, Niko; Reiss, Peter

    2016-05-01

    A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields ultra-compact, stable, and highly luminescent antibody-QD conjugates suitable for use in FRET immunoassays. Hydrophobic InPZnS/ZnSe/ZnS (emission wavelength: 530 nm), CdSe/ZnS (605 nm), and CdSeTe/ZnS (705 nm) QDs were surface functionalized with zwitterionic penicillamine, enabling aqueous phase transfer under conservation of the photoluminescence properties. Post-functionalization with a heterobifunctional crosslinker, containing a lipoic acid group and a maleimide function, enabled the subsequent coupling to sulfhydryl groups of proteins. This was demonstrated by QD conjugation with fragmented antibodies (F(ab)). The obtained F(ab)-QD conjugates range among the smallest antibody-functionalized nanoprobes ever reported, with a hydrodynamic diameter <13 nm, PL quantum yield up to 66% at 705 nm, and colloidal stability of several months in various buffers. They were applied as FRET acceptors in homogeneous, time-gated immunoassays using Tb-antibodies as FRET donors, both coupled by an immunological sandwich complex between the two antibodies and a PSA (prostate specific antigen) biomarker. The advantages of the compact surface coating for FRET could be demonstrated by an 6.2 and 2.5 fold improvement of the limit of detection (LOD) for PSA compared to commercially available hydrophilic QDs emitting at 605 and 705 nm, respectively. While the commercial QDs contain identical inorganic cores responsible for their fluorescence, they are coated with a comparably thick amphiphilic polymer layer leading to much larger hydrodynamic diameters (>26 nm without biomolecules). The LODs of 0.8 and 3.7 ng mL-1 obtained in 50 μL serum samples are below the clinical cut-off level of PSA (4 ng mL-1) and demonstrate their direct applicability in clinical diagnostics.A novel two-step approach for quantum dot (QD) functionalization and bioconjugation is presented, which yields

  10. Micromotor-based lab-on-chip immunoassays.

    PubMed

    García, Miguel; Orozco, Jahir; Guix, Maria; Gao, Wei; Sattayasamitsathit, Sirilak; Escarpa, Alberto; Merkoçi, Arben; Wang, Joseph

    2013-02-21

    Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic polymer/Ni/Pt microtube engine, containing carboxy moieties on its mixed poly(3,4-ethylenedioxythiophene) (PEDOT)/COOH-PEDOT polymeric outermost layer, is further functionalized with the antibody receptor to selectively recognize and capture the target protein. The new motor-based microchip immunoassay operations are carried out without any bulk fluid flow, replacing the common washing steps in antibody-based protein bioassays with the active transport of the captured protein throughout the different reservoirs, where each step of the immunoassay takes place. A first microchip format involving an 'on-the-fly' double-antibody sandwich assay (DASA) is used for demonstrating the selective capture of the target protein, in the presence of excess of non-target proteins. A secondary antibody tagged with a polymeric-sphere tracer allows the direct visualization of the binding events. In a second approach the immuno-nanomotor captures and transports the microsphere-tagged antigen through a microchannel network. An anti-protein-A modified microengine is finally used to demonstrate the selective capture, transport and convenient label-free optical detection of a Staphylococcus aureus target bacteria (containing proteinA in its cell wall) in the presence of a large excess of non-target (Saccharomyces cerevisiae) cells. The resulting nanomotor-based microchip immunoassay offers considerable potential for diverse applications in clinical diagnostics, environmental and security monitoring fields. PMID:23123833

  11. Fast and Sensitive Detection of Enteropathogenic Yersinia by Immunoassays

    PubMed Central

    Laporte, Jérôme; Savin, Cyril; Lamourette, Patricia; Devilliers, Karine; Volland, Hervé; Carniel, Elisabeth; Créminon, Christophe

    2014-01-01

    Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. Monoclonal antibodies (MAbs) directed against Y. enterocolitica bioserotypes 2/O:9 and 4/O:3 and Y. pseudotuberculosis serotypes I and III were produced. Pairs of MAbs were selected by testing their specificity and affinity for enteropathogenic Yersinia and other commonly found enterobacteria. Pairs of MAbs were selected to develop highly sensitive enzyme immunoassays (EIAs) and lateral flow immunoassays (LFIs or dipsticks) convenient for the purpose of rapid diagnosis. The limit of detection of the EIAs ranged from 3.2 × 103 CFU/ml to 8.8 × 104 CFU/ml for pathogenic serotypes I and III of Y. pseudotuberculosis and pathogenic bioserotypes 2/O:9 and 4/O:3 of Y. enterocolitica and for the LFIs ranged from 105 CFU/ml to 106 CFU/ml. A similar limit of detection was observed for artificially contaminated human feces. PMID:25355759

  12. Fast and sensitive detection of enteropathogenic Yersinia by immunoassays.

    PubMed

    Laporte, Jérôme; Savin, Cyril; Lamourette, Patricia; Devilliers, Karine; Volland, Hervé; Carniel, Elisabeth; Créminon, Christophe; Simon, Stéphanie

    2015-01-01

    Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. Monoclonal antibodies (MAbs) directed against Y. enterocolitica bioserotypes 2/O:9 and 4/O:3 and Y. pseudotuberculosis serotypes I and III were produced. Pairs of MAbs were selected by testing their specificity and affinity for enteropathogenic Yersinia and other commonly found enterobacteria. Pairs of MAbs were selected to develop highly sensitive enzyme immunoassays (EIAs) and lateral flow immunoassays (LFIs or dipsticks) convenient for the purpose of rapid diagnosis. The limit of detection of the EIAs ranged from 3.2 × 10(3) CFU/ml to 8.8 × 10(4) CFU/ml for pathogenic serotypes I and III of Y. pseudotuberculosis and pathogenic bioserotypes 2/O:9 and 4/O:3 of Y. enterocolitica and for the LFIs ranged from 10(5) CFU/ml to 10(6) CFU/ml. A similar limit of detection was observed for artificially contaminated human feces. PMID:25355759

  13. New biologically active hydrogen sulfide donors.

    PubMed

    Roger, Thomas; Raynaud, Francoise; Bouillaud, Frédéric; Ransy, Céline; Simonet, Serge; Crespo, Christine; Bourguignon, Marie-Pierre; Villeneuve, Nicole; Vilaine, Jean-Paul; Artaud, Isabelle; Galardon, Erwan

    2013-11-25

    Generous donors: The dithioperoxyanhydrides (CH3 COS)2 , (PhCOS)2 , CH3 COSSCO2 Me and PhCOSSCO2 Me act as thiol-activated hydrogen sulfide donors in aqueous buffer solution. The most efficient donor (CH3 COS)2 can induce a biological response in cells, and advantageously replace hydrogen sulfide in ex vivo vascular studies. PMID:24115650

  14. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GENERAL REQUIREMENTS FOR BLOOD, BLOOD COMPONENTS, AND BLOOD DERIVATIVES § 630.6 Donor notification. (a) Notification of donors. You, an establishment that collects blood or blood components, must make reasonable... of donation of blood or blood components that the donor should not donate in the future; (3)...

  15. Pholcodine interference in the immunoassay for opiates in urine.

    PubMed

    Svenneby, G; Wedege, E; Karlsen, R L

    1983-01-01

    The excretion in urine after single oral therapeutic doses of morphine derivatives was analysed with radioimmunoassay (RIA) and homogeneous enzyme immunoassay (EMIT) for opiates. In contrast to the rapid excretion of ethylmorphine and codeine, pholcodine showed positive results for opiates 2-6 weeks after intake when the urines were analysed with the RIA-method. When analysed with the EMIT-method, positive results were obtained for pholcodine for approximately 10 days. As pholcodine is a common component in cough mixtures, its prolonged excretion could represent a hazard in interpreting the results from drug analyses of urines. PMID:6347841

  16. Chemiluminescence enzyme immunoassay using ProteinA-bacterial magnetite complex

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tadashi; Sato, Rika; Kamiya, Shinji; Tanaka, Tsuyosi; Takeyama, Haruko

    1999-04-01

    Bacterial magnetic particles (BMPs) which have ProteinA expressed on their surface were constructed using magA which is a key gene in BMP biosynthesis in the magnetic bacterium Magnetospirillum sp. AMB-1. Homogenous chemiluminescence enzyme immunoassay using antibody bound ProteinA-BMP complexes was developed for detection of human IgG. A good correlation between the luminescence yield and the concentration of human IgG was obtained in the range of 1-10 3 ng/ml.

  17. Diagnostic immunoassay by solid phase separation for digoxin

    SciTech Connect

    Grenier, F.C.; Pry, T.A.; Kolaczkowski, L.

    1988-11-29

    A method is described for conducting a diagnostic immunoassay for digoxin, comprising: (a) forming a reaction mixture of a test sample with a molar excess of labeled anti-digoxin antibodies whereby the labeled antibodies are capable of forming complex with digoxin present in the sample; (b) contacting the reaction mixture with a solid phase material having immobilized thereon a compound; (c) separating the solid phase material from the reaction mixture; and (d) determining the presence of digoxin in the test sample by measuring the amount of complex present in the liquid phase.

  18. Tumor specific lung cancer diagnostics with multiplexed FRET immunoassays

    NASA Astrophysics Data System (ADS)

    Geißler, D.; Hill, D.; Löhmannsröben, H.-G.; Thomas, E.; Lavigne, A.; Darbouret, B.; Bois, E.; Charbonnière, L. J.; Ziessel, R. F.; Hildebrandt, N.

    2010-02-01

    An optical multiplexed homogeneous (liquid phase) immunoassay based on FRET from a terbium complex to eight different fluorescent dyes is presented. We achieved highly sensitive parallel detection of four different lung cancer specific tumor markers (CEA, NSE, SCC and CYFRA21-1) within a single assay and show a proof-of-principle for 5- fold multiplexing. The method is well suited for fast and low-cost miniaturized point-of-care testing as well as for highthroughput screening in a broad range of in-vitro diagnostic applications.

  19. Demonstration of four immunoassay formats using the array biosensor

    NASA Technical Reports Server (NTRS)

    Sapsford, Kim E.; Charles, Paul T.; Patterson, Charles H Jr; Ligler, Frances S.

    2002-01-01

    The ability of a fluorescence-based array biosensor to measure and quantify the binding of an antigen to an immobilized antibody has been demonstrated using the four different immunoassay formats: direct, competitive, displacement, and sandwich. A patterned array of antibodies specific for 2,4,6-trinitrotoluene (TNT) immobilized onto the surface of a planar waveguide and used to measure signals from different antigen concentrations simultaneously. For direct, competitive, and displacement assays, which are one-step assays, measurements were obtained in real time. Dose-response curves were calculated for all four assay formats, demonstrating the array biosensor's ability to quantify the amount of antigen present in solution.

  20. Application Of Laser Fluorimetry To Enzyme-Linked Immunoassay

    NASA Astrophysics Data System (ADS)

    Hinsberg, William D.; Milby, Kristin H.; Lidofsky, Steven D.; Zare, Richard N.

    1981-09-01

    An enzyme-linked sandwich immunoassay for insulin is described. Horseradish peroxidase is employed as an enzyme label for antibody, and enzyme activity is measured via the fluorogenic substrate, p-hydroxyphenylacetic acid. The product is detected by excitation of fluorescence with the 325 nm line of a cw helium-cadmium ion laser on-line with reverse phase high performance liquid chromatography. The method requires a total incubation time of 45 minutes, and the limit of insulin detection is 1.1 μU/ml (6.6 pM). This assay is applicable to the analysis of human serum samples.

  1. Detection of Hepatitis E Virus Genotype 1 Among Blood Donors From Southwest of Iran

    PubMed Central

    Parsa, Rahil; Adibzadeh, Setare; Behzad Behbahani, Abbas; Farhadi, Ali; Yaghobi, Ramin; Rafiei Dehbidi, Gholam Reza; Hajizamani, Saeideh; Rahbar, Sanaz; Nikouyan, Negin; Okhovat, Mohammad Ali; Naderi, Samaneh; Salehi, Saeede; Alizadeh, Marzieh; Ranjbaran, Reza; Zarnegar, Golnoosh; Alavi, Parnian

    2016-01-01

    Background Infection with hepatitis E virus (HEV) is endemic in developing countries and reveals significant regional differences. Several studies have reported virus transmission via blood transfusion. To date, however, no cases of HEV RNA detection in blood donors have been reported from Iran. Objectives The aim of this study was to determine the presence of HEV RNA in plasma samples of blood donors referred to a blood transfusion center in Shiraz in the southwest of Iran. The HEV genotypes were also investigated using nucleotide sequencing. Patients and Methods Blood samples were collected from 700 blood donors who were referred to Fars blood transfusion organization from January to March 2014. Plasma samples were screened for the presence of HEV IgG and IgM antibodies by standard enzyme immunoassay. Samples seroreactive to anti-HEV were further tested for the presence of HEV RNA using nested polymerase chain reaction (PCR) with universal primers for detection of all four HEV genotypes. Positive PCR samples were then subjected to DNA sequencing for further analysis. Results Fifty (50, 7.1%) out of 700 plasma samples tested positive for anti-HEV antibodies. HEV RNA was detected in 7/50 (12%) of the antibody-positive samples, the majority of which were IgM positive. Sequence analysis of seven isolates of the HEV RNA ORF 2 gene region revealed > 80% similarity with genotype 1. Conclusions The analysis indicates that the HEV isolated from blood donors in the southwest of Iran belongs to genotype 1. However, more samples from other geographic regions of Iran are needed to confirm these findings. Because transmission of HEV by administration of blood or blood components is likely to occur, it may be sensible to screen donor blood for HEV to eliminate transfusion-transmitted HEV infection when the recipient is immunocompromised.

  2. DEVELOPMENT OF A CLASS-SELECTIVE ENZYME IMMUNOASSAY FOR URINARY PHENOLIC GLUCURONIDES. (R825433)

    EPA Science Inventory

    Class-selective immunoassays for the measurement of glucuronides in human urine can aid evaluation of human exposure to complex mixtures of xenobiotics. Therefore, an enzyme immunoassay (EIA) for the group-selective detection of phenolic Hyperbilirubinemia in normal healthy donors

    PubMed Central

    Arora, Veena; Kulkarni, R. K.; Cherian, Susan; Pillai, Raji; Shivali, M.

    2009-01-01

    The present study was carried out in B.A.R.C. Hospital Blood Bank over a span of five years, and includes 2734 donors. All the bags were screened for HIV, HBsAg, HCV and VDRL and the plasma in the pilot tubes of the blood bags was observed to detect any abnormality in color. In 27 cases plasma was found to be icteric and liver function tests were carried out on these samples. Two donors showed higher SGPT level, and were excluded. No significant increases in liver enzymes were recorded in the others. Causes of icteric plasma in these apparently healthy donors are discussed. Differential diagnosis includes Gilbert’s disease, hemolytic anemia, drug-induced anemia and other hepatic causes of hyperbilirubinemia, of which Gilbert’s disease is most probable cause with a prevalence of 0.91% in our population. As there are no studies to document the safety of the recipients receiving such abnormal colored plasma as well as to document the hazards in its transfusion, the question arises whether to transfuse such units or not. This study highlights this dilemma. A reassessment of existing policies and regulations is merited. PMID:20808649

  3. Changing Pattern of Donor Selection Criteria in Deceased Donor Liver Transplant: A Review of Literature

    PubMed Central

    Routh, Dronacharya; Naidu, Sudeep; Sharma, Sanjay; Ranjan, Priya; Godara, Rajesh

    2013-01-01

    During the last couple of decades, with standardization and progress in surgical techniques, immunosuppression and post liver transplantation patient care, the outcome of liver transplantation has been optimized. However, the principal limitation of transplantation remains access to an allograft. The number of patients who could derive benefit from liver transplantation markedly exceeds the number of available deceased donors. The large gap between the growing list of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donor pool and identify new avenues. This article reviews the changing pattern of donor for liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis), donation after cardiac death, use of partial grafts (split liver grafts) and other suboptimal donors (hypernatremia, infections, hypotension and inotropic support). PMID:25755521

  4. Species Specific Bacterial Spore Detection Using Lateral-Flow Immunoassay with DPA-Triggered Tb Luminescence

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian

    2003-01-01

    A method of detecting bacterial spores incorporates (1) A method of lateral-flow immunoassay in combination with (2) A method based on the luminescence of Tb3+ ions to which molecules of dipicolinic acid (DPA) released from the spores have become bound. The present combination of lateral-flow immunoassay and DPA-triggered Tb luminescence was developed as a superior alternative to a prior lateral-flow immunoassay method in which detection involves the visual observation and/or measurement of red light scattered from colloidal gold nanoparticles. The advantage of the present combination method is that it affords both (1) High selectivity for spores of the species of bacteria that one seeks to detect (a characteristic of lateral-flow immunoassay in general) and (2) Detection sensitivity much greater (by virtue of the use of DPA-triggered Tb luminescence instead of gold nanoparticles) than that of the prior lateral-flow immunoassay method

  5. Immunoassay Methods and their Applications in Pharmaceutical Analysis: Basic Methodology and Recent Advances

    PubMed Central

    Darwish, Ibrahim A.

    2006-01-01

    Immunoassays are bioanalytical methods in which the quantitation of the analyte depends on the reaction of an antigen (analyte) and an antibody. Immunoassays have been widely used in many important areas of pharmaceutical analysis such as diagnosis of diseases, therapeutic drug monitoring, clinical pharmacokinetic and bioequivalence studies in drug discovery and pharmaceutical industries. The importance and widespread of immunoassay methods in pharmaceutical analysis are attributed to their inherent specificity, high-throughput, and high sensitivity for the analysis of wide range of analytes in biological samples. Recently, marked improvements were achieved in the field of immunoassay development for the purposes of pharmaceutical analysis. These improvements involved the preparation of the unique immunoanalytical reagents, analysis of new categories of compounds, methodology, and instrumentation. The basic methodologies and recent advances in immunoassay methods applied in different fields of pharmaceutical analysis have been reviewed. PMID:23674985

  6. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF THREE IMMUNOASSAY TEST KITS FOR ANTHRAX, BOTULINUM TOXIN AND RICIN

    EPA Science Inventory

    Immunoassay test kits are based on immunoassay methods, where specific antibodies are used to detect and measure the contaminants of interest. Immunoassay test kits rely on the reaction of a contaminant or antigen with a selective antibody to give a product that can be measures....

  7. The development of immunoassays for detection of chemical warfare agents

    SciTech Connect

    Lenz, D.E.

    1995-06-01

    With the advent of enzyme linked immunoabsorbant assays (ELISA) and monoclonal antibodies in the last two decades, there has been considerable effort devoted to the development of antibodies to detect and quantify low molecular weight toxic substances in environmental or biological fluids. Polyclonal antibodies against paraoxon (the toxic metabolite of parathion) were reported as capable of detecting paraoxon in body fluids at a level of 10{sup -9} M ({approximately}260 pg/mL) when used in a competitive inhibition enzyme immunoassay (CIEIA). Monoclonal antibodies developed against a structural analogue of the chemical warfare agent soman were capable of detecting soman in buffer solutions at a level of 10{sup -6} M ({approximately}180 ng/mL). In addition, these antibodies were highly specific for soman even in the presence of its major hydrolysis product. Subsequent studies with antisoman monoclonal antibodies reported an extension of the level of sensitivity to -80 ng/mL. Furthermore these antibodies did not cross react with other chemical warfare nerve agents such as sarin or tabun. In all cases, the time for a confirmatory test was two hours or less. Immunoassays for T-2 micotoxins have also been reported with a minimal detection range of 2 pg/assay to 50 ng/assay for the polyclonal and monoclonal T-2 antibodies respectively. These antibodies offer a sensitive, rapid and low cost approach to the diagnosis or detection of the presence of toxic chemical substances.

  8. Colorimetric multiplexed immunoassay for sequential detection of tumor markers.

    PubMed

    Wang, Jing; Cao, Ya; Xu, Yuanyuan; Li, Genxi

    2009-10-15

    In this paper, a very simple and easily-operated colorimetric multiplexed immunoassay method for sequential detection of tumor markers has been presented. Magnetic microparticles which are conjugated with biotinylated antibodies are firstly added into the test solution. After fast magnetic collection, these complexes are separated from non-specific proteins. Through different enzymatic reactions of 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD) catalyzed by horseradish peroxidase molecules which are loaded on the surfaces of gold nanoparticles, two antigens carcinoembryonic antigen and alpha-fetoprotein can be detected even with naked eyes. The detection limit obtained from the spectrophotometric measurements is as low as 0.02 ng/mL. This proposed method also has high specificity and reproducibility, as well as excellent efficiency of 94 min for the detection of serum samples. So, this new multiplexed immunoassay method might be a promising approach for the diagnosis of cancer and some other diseases in clinical applications. PMID:19726177

  9. Aequorin fusion proteins as bioluminescent tracers for competitive immunoassays

    NASA Astrophysics Data System (ADS)

    Mirasoli, Mara; Michelini, Elisa; Deo, Sapna K.; Dikici, Emre; Roda, Aldo; Daunert, Sylvia

    2004-06-01

    The use of bio- and chemiluminescence for the development of quantitative binding assays offers undoubted advantages over other detection systems, such as spectrophotometry, fluorescence, or radioactivity. Indeed, bio- and chemiluminescence detection provides similar, or even better, sensitivity and detectability than radioisotopes, while avoiding the problems of health hazards, waste disposal, and instability associated with the use of radioisotopes. Among bioluminescent labels, the calcium-activated photoprotein aequorin, originally isolated from Aequorea victoria and today available as a recombinant product, is characterized by very high detectability, down to attomole levels. It has been used as a bioluminescent label for developing a variety of highly sensitive immunoassays, using various analyte-aequorin conjugation strategies. When the analyte is a protein or a peptide, genetic engineering techniques can be used to produce protein fusions where the analyte is in-frame fused with aequorin, thus producing homogeneous one-to-one conjugation products, available in virtually unlimited amount. Various assays were developed using this strategy: a short review of the most interesting applications is presented, as well as the cloning, purification and initial characterization of an endothelin-1-aequorin conjugate suitable for developing a competitive immunoassay for endothelin-1, a potent vasoconstrictor peptide, involved in hypertension.

  10. [Laser-time-resolved fluorescence spectroscopy in immunoassays].

    PubMed

    Pan, L; Du, J; Xie, W; Du, Q; Yun, Q

    2000-06-01

    This paper described a laser-excited time-resolved fluoroimmunoassay set. It made lanthanide ion to couple the anhydrde of diethylenetriaminepentaacetic acid (DTPAA) for labeling antibodies. The experiment used polystyrene tap coated with HCV antigen as the solid phase and a chelate of the rare earth metal europium as fluorescent label. A nitrogen laser beam was used to excite the Eu3- chelates and after 60 microseconds delay time, the emission fluorescence was measured. Background fluorescence of short lifetimes caused by serum components and Raman scattering can be eliminated by set the delay time. In the system condition, fluorescent spectra and fluorescent lifetimes of Eu3+ beta-naphthoyltrifluroacetone (NTA) chelates were measured. The fluorescent lifetime value is 650 microseconds. The maximum emission wavelength is 613 nm. The linear range of europium ion concentration is 1 x 10(-7)-1 x 10(-11) g.mL-1 and the detection limit is 1 x 10(-13) g.mL-1. The relative standard deviation of determination (n = 12) for samples at 0.01 ng.mL-1 magnitude is 6.4%. Laser-TRFIA was also found to be suitable for diagnosis of HCV. The sensitivity and specificity were comparable to enzyme immunoassay. The result was obtained with laser-TRFIA for 29 human correlated well with enzyme immunoassay. PMID:12958930

  11. Sensitive chemiluminescent immunoassay of triclopyr by digital image analysis.

    PubMed

    Díaz, Aurora N; Sánchez, Francisco G; Baro, Enrique N; Díaz, Ana F G; Aguilar, Alfonso; Algarra, Manuel

    2012-08-15

    An image based detection of chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) for the quantification of triclopyr has been developed. The immunoassay was an indirect competitive immunoassay with an anti-rabbit secondary antibody conjugated to horseradish peroxidase (HRP). Chemiluminescence was produced by the luminol/H(2)O(2)/HRP reaction, detected by a monochrome video CCD camera and digitized with an Imagraph IC-PCI frame grabber using a custom program developed in C(++) (Microsoft Visual C(++) 6.0). Two main improvements are reported in the data processing software: the implementation of a circular mesh covering the perimeter of each well, eliminating diffuse light from the neighboring wells, and the use of volume (the integration of light intensity of all pixels that define a well) as an analytical signal instead of CL intensity or area (as usual in commercial plate readers) to improve precision for normalization of the total light output. The standard curve was produced for 0.01-10 ng/L triclopyr. The limit of detection was 0.8 ng/L and the variation coefficient was 3.07% (n=10, P=0.05). PMID:22841045

  12. Sensitive Immunoassays of Nitrated Fibrinogen in Human Biofluids

    SciTech Connect

    Tang, Zhiwen; Wu, Hong; Du, Dan; Wang, Jun; Wang, Hua; Qian, Weijun; Bigelow, Diana J.; Pounds, Joel G.; Smith, Richard D.; Lin, Yuehe

    2010-05-05

    Three new sandwich immunoassays for detection of nitrated biomarker have been established with potential applications in biomedical studies and clinical practice. In this study, nitrated human fibrinogen, a potential oxidative stress biomarker for several pathologies, was chosen as the target. To improve the sensitivity and overcome the interference caused by the complexity of human biofluids, we developed three sandwich strategies using various combinations of primary antibody and secondary antibody. All three strategies demonstrated high sensitivity and selectivity towards nitrated forms of fibrinogen in buffer, but their performances were dramatically reduced when tested with human plasma and serum samples. Systematically optimizations were carried out to investigate the effects of numerous factors, including sampling, coating, blocking, and immunoreactions. Our final optimization results indicate that two of these strategies retain sufficient sensitivity and selectivity for use as assays in human physiological samples. Specifically, detection limits reached the pM level and the linear response ranges were up to nM level with a correlation coefficient > 0.99. To our best knowledge, this is the first example of using an electrochemical immunoassay for a nitrated biomarker in a physiological fluid. This novel approach provides a rapid, sensitive, selective, cost efficient and robust bioassay for detection of oxidative stress in pathology and for clinical applications. Moreover, the sandwich strategies developed in this paper can be readily used to establish effective methods targeting other nitration biomarkers.

  13. Quantum-Dots Based Electrochemical Immunoassay of Interleukin-1α

    SciTech Connect

    Wu, Hong; Liu, Guodong; Wang, Jun; Lin, Yuehe

    2007-07-01

    We describe a quantum-dot (QD, CdSe@ZnS)-based electrochemical immunoassay to detect a protein biomarker, interleukin-1α (IL-1α). QD conjugated with anti-IL-1α antibody was used as a label in an immunorecognition event. After a complete sandwich immunoreaction among the primary IL-1α antibody (immobilized on the avidin-modified magnetic beads), IL-1α, and the QD-labeled secondary antibody, QD labels were attached to the magnetic-bead surface through the antibody-antigen immunocomplex. Electrochemical stripping analysis of the captured QDs was used to quantify the concentration of IL-1α after an acid-dissolution step. The streptavidin-modified magnetic beads and the magnetic separation platform were used to integrate a facile antibody immobilization (through a biotin/streptavidin interaction) with immunoreactions and the isolation of immunocomplexes from reaction solutions in the assay. The voltammetric response is highly linear over the range of 0.5 to 50 ng mL-1 IL 1α, and the limit of detection is estimated to be 0.3 ng mL-1 (18 pM). This QD-based electrochemical immunoassay shows great promise for rapid, simple, and cost-effective analysis of protein biomarkers.

  14. Detection of the Antimicrobial Triclosan in Environmental Samples by Immunoassay.

    PubMed

    Ahn, Ki Chang; Ranganathan, Anupama; Bever, Candace S; Hwang, Sung Hee; Holland, Erika B; Morisseau, Kevin; Pessah, Isaac N; Hammock, Bruce D; Gee, Shirley J

    2016-04-01

    A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for the detection of the antimicrobial triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) was developed. Novel immunizing haptens were synthesized by derivatizing at the 4-Cl position of the TCS molecule. Compounds derived from substitutions at 4'-Cl and that replaced the 2'-OH with a Cl atom were designed as unique coating antigen haptens. Polyclonal rabbit antisera were screened against the coating antigen library to identify combinations of immunoreagents resulting in the most sensitive assays. The most sensitive assay identified was one utilizing antiserum no. 1155 and a heterologous competitive hapten, where the 2'-OH group was substituted with a Cl atom. An IC50 value and the detection range for TCS in assay buffer were 1.19 and 0.21-6.71 μg/L, respectively. The assay was selective for TCS, providing low cross-reactivity (<5%) to the major metabolites of TCS and to brominated diphenyl ether-47. A second assay utilizing a competitive hapten containing Br instead of Cl substitutions was broadly selective for both brominated and chlorinated diphenylethers. Using the most sensitive assay combination, we measured TCS concentrations in water samples following dilution. Biosolid samples were analyzed following the dilution of a simple solvent extract. The immunoassay results were similar to those determined by LC-MS/MS. This immunoassay can be used as a rapid and convenient tool to screen for human and environmental exposure. PMID:26937944

  15. Bioluminescent detection probe for tick-borne encephalitis virus immunoassay.

    PubMed

    Burakova, Ludmila P; Kudryavtsev, Alexander N; Stepanyuk, Galina A; Baykov, Ivan K; Morozova, Vera V; Tikunova, Nina V; Dubova, Maria A; Lyapustin, Victor N; Yakimenko, Valeri V; Frank, Ludmila A

    2015-07-01

    To facilitate the detection of the tick-borne encephalitis virus (TBEV), the causative agent of one of the most severe human neuroinfections, we have developed an immunoassay based on bioluminescent hybrid protein 14D5a-Rm7 as a detection probe. The protein containing Renilla luciferase as a reporter and a single-chain variable fragment (scFv) of murine immunoglobulin to TBEV as a recognition element was constructed, produced by bacterial expression, purified, and tested. Both domains were shown to reveal their specific biological properties-affinity to the target antigen and bioluminescent activity. Hybrid protein was applied as a label for solid-phase immunoassay of the antigens, associated with the tick-borne encephalitis virus (native glycoprotein E or extracts of the infected strain of lab ticks). The assay demonstrates high sensitivity (0.056 ng of glycoprotein E; 10(4)-10(5) virus particles or 0.1 pg virions) and simplicity and is competitive with conventional methods for detection of TBEV. PMID:25925861

  16. Development of an Heterologous Immunoassay for Ciprofloxacin Residue in Milk

    NASA Astrophysics Data System (ADS)

    Jinqing, Jiang; Haitang, Zhang; Zhixing, An; Zhiyong, Xu; Xuefeng, Yang; Huaguo, Huang; Ziliang, Wang

    A heterologous immunoassay has been developed for the determination of Ciprofloxacin (CPFX) residues in milk. For this reason, carbodiimide active ester method was employed to synthesize the artificial antigen of CPFX-BSA, and mixed anhydride reaction was used to prepare the coating antigen of CPFX-OVA to pursue the heterologous sensitivity. Based on the square matrix titration, an icELISA method was developed for the quantitative detection of CPFX in cattle milk. The dynamic range was from 0.036 to 92.5 ng/mL, with LOD and IC50 value of 0.019 ng/mL and 1.8 ng/mL, respectively. Except for a high cross-reactivity (89.7%) to Enrofloxacin, negligible cross-reactivity to the other compounds was observed. After optimization, 0.03 mol/L of HCl, or 10% of methanol was used in the assay buffer. 20-fold dilution in cattle milk gave an inhibition curve almost the same as that in PBS buffer. The regression equation for this assay was y = 0.9036 x + 1.4574, with a correlation coefficient (R2) of 0.9844. The results suggest the veracity of the heterologous immunoassay for detecting CPFX residue in milk.

  17. Multiplex Detection of Plant Pathogens Using a Microsphere Immunoassay Technology

    PubMed Central

    Charlermroj, Ratthaphol; Himananto, Orawan; Seepiban, Channarong; Kumpoosiri, Mallika; Warin, Nuchnard; Oplatowska, Michalina; Gajanandana, Oraprapai; Grant, Irene R.; Karoonuthaisiri, Nitsara; Elliott, Christopher T.

    2013-01-01

    Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), chilli vein-banding mottle virus (CVbMV, potyvirus), watermelon silver mottle virus (WSMoV, tospovirus serogroup IV) and melon yellow spot virus (MYSV, tospovirus). An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE)-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA) when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour) was much shorter than that of ELISA (4 hours). This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection. PMID:23638044

  18. Seroprevalence and Associated Risk Factors for Toxoplasma gondii Infection in Healthy Blood Donors: A Cross-Sectional Study in Sonora, Mexico.

    PubMed

    Alvarado-Esquivel, Cosme; Rascón-Careaga, Antonio; Hernández-Tinoco, Jesús; Corella-Madueño, María Alba Guadalupe; Sánchez-Anguiano, Luis Francisco; Aldana-Madrid, María Lourdes; Velasquez-Vega, Edgar; Quizán-Plata, Trinidad; Navarro-Henze, José Luis; Badell-Luzardo, Joel Alberto; Gastélum-Cano, José María; Liesenfeld, Oliver

    2016-01-01

    Toxoplasma gondii (T. gondii) can be transmitted by blood transfusion. We determined the prevalence of T. gondii infection in healthy blood donors in Hermosillo city, Mexico, and the association of infection with T. gondii with the sociodemographic, clinical, and behavioral characteristics of blood donors. Four hundred and eight blood donors who attended two public blood banks in Hermosillo city were examined for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays. Of the 408 blood donors (mean age 31.77 ± 9.52; range 18-60 years old) studied, 55 (13.5%) were positive for anti-T. gondii IgG antibodies, and 12 (21.8%) of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that seropositivity to T. gondii was associated with age (OR = 1.74; 95% CI: 1.03-2.94; P = 0.03) and tobacco use (OR = 2.09; 95% CI: 1.02-4.29; P = 0.04). Seropositivity to T. gondii was correlated with the number of pregnancies, deliveries, and cesarean sections. The seroprevalence of T. gondii infection in blood donors in Sonora is the highest reported in blood donors in northern Mexico so far. This is the first report of an association of T. gondii exposure and tobacco use. Further research to confirm this association is needed. PMID:27446960

  19. Seroprevalence and Associated Risk Factors for Toxoplasma gondii Infection in Healthy Blood Donors: A Cross-Sectional Study in Sonora, Mexico

    PubMed Central

    Alvarado-Esquivel, Cosme; Rascón-Careaga, Antonio; Hernández-Tinoco, Jesús; Corella-Madueño, María Alba Guadalupe; Sánchez-Anguiano, Luis Francisco; Aldana-Madrid, María Lourdes; Velasquez-Vega, Edgar; Quizán-Plata, Trinidad; Navarro-Henze, José Luis; Badell-Luzardo, Joel Alberto; Gastélum-Cano, José María; Liesenfeld, Oliver

    2016-01-01

    Toxoplasma gondii (T. gondii) can be transmitted by blood transfusion. We determined the prevalence of T. gondii infection in healthy blood donors in Hermosillo city, Mexico, and the association of infection with T. gondii with the sociodemographic, clinical, and behavioral characteristics of blood donors. Four hundred and eight blood donors who attended two public blood banks in Hermosillo city were examined for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays. Of the 408 blood donors (mean age 31.77 ± 9.52; range 18–60 years old) studied, 55 (13.5%) were positive for anti-T. gondii IgG antibodies, and 12 (21.8%) of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that seropositivity to T. gondii was associated with age (OR = 1.74; 95% CI: 1.03–2.94; P = 0.03) and tobacco use (OR = 2.09; 95% CI: 1.02–4.29; P = 0.04). Seropositivity to T. gondii was correlated with the number of pregnancies, deliveries, and cesarean sections. The seroprevalence of T. gondii infection in blood donors in Sonora is the highest reported in blood donors in northern Mexico so far. This is the first report of an association of T. gondii exposure and tobacco use. Further research to confirm this association is needed. PMID:27446960

  1. Donor free radical explosive composition

    DOEpatents

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  2. Gamete donors' expectations and experiences of contact with their donor offspring

    PubMed Central

    Kirkman, Maggie; Bourne, Kate; Fisher, Jane; Johnson, Louise; Hammarberg, Karin

    2014-01-01

    STUDY QUESTION What are the expectations and experiences of anonymous gamete donors about contact with their donor offspring? SUMMARY ANSWER Rather than consistently wanting to remain distant from their donor offspring, donors' expectations and experiences of contact with donor offspring ranged from none to a close personal relationship. WHAT IS KNOWN ALREADY Donor conception is part of assisted reproduction in many countries, but little is known about its continuing influence on gamete donors' lives. STUDY DESIGN, SIZE, DURATION A qualitative research model appropriate for understanding participants' views was employed; semi-structured interviews were conducted during January–March 2013. PARTICIPANTS/MATERIALS, SETTING, METHODS Before 1998, gamete donors in Victoria, Australia, were subject to evolving legislation that allowed them to remain anonymous or (from 1988) to consent to the release of identifying information. An opportunity to increase knowledge of donors' expectations and experiences of contact with their donor offspring recently arose in Victoria when a recommendation was made to introduce mandatory identification of donors on request from their donor offspring, with retrospective effect. Pre-1998 donors were invited through an advertising campaign to be interviewed about their views, experiences and expectations; 36 sperm donors and 6 egg donors participated. MAIN RESULTS AND THE ROLE OF CHANCE This research is unusual in achieving participation by donors who would not normally identify themselves to researchers or government inquiries. Qualitative thematic analysis revealed that most donors did not characterize themselves as parents of their donor offspring. Donors' expectations and experiences of contact with donor offspring ranged from none to a close personal relationship. LIMITATIONS, REASONS FOR CAUTION It is not possible to establish whether participants were representative of all pre-1998 donors. WIDER IMPLICATIONS OF THE FINDINGS Anonymous

  3. Development of an Ultrasensitive Immunoassay for Detecting Tartrazine

    PubMed Central

    Li, Zhuokun; Song, Shanshan; Xu, Liguang; Kuang, Hua; Guo, Shidong; Xu, Chuanlai

    2013-01-01

    We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages. PMID:23799494

  4. New developments in particle-based tests and immunoassays.

    PubMed

    Bangs, L B

    1990-09-01

    Latex agglutination tests were invented in 1957. Thirty years later, new tests are still being devised and applied to new analytes. Reproducibility and readability continue to improve. Qualitative tests have now evolved to quantitative particle immunoassays: agglutination is detected by spectrophotometers or nephelometers, in tubes or 96-well plates. These same particles are now also being used in particle capture ELIST and ELISA (enzyme linked immunosorbent tests and assays) where particles are caught upon a filter and act as supports for sandwich tests (those "+/-" or "blue-dot" tests). These also can be quantified, as in the Abbott IM x assay system. Dyed microspheres now function as the color tags in over-the-counter sandwich-type pregnancy tests. In the future, results from assays using this technology could be read on reflectometers (strip readers). Currently, magnetic particles are used in solid phase radioimmunoassays and DNA probes. PMID:10148953

  5. Nanoparticle-based immunosensors and immunoassays for aflatoxins.

    PubMed

    Wang, Xu; Niessner, Reinhard; Tang, Dianping; Knopp, Dietmar

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety. PMID:26920768

  6. A redox-mediated chromogenic reaction and application in immunoassay.

    PubMed

    Yu, Ru-Jia; Ma, Wei; Peng, Mao-Pan; Bai, Zhi-Shan; Long, Yi-Tao

    2016-08-31

    A novel redox-mediated chromogenic reaction was demonstrated based on the reaction between HAuCl4 and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which generate various color responses from red to green in the resulting solutions. Various redox substance could be used to mediate the reaction and trigger a distinct color response. We established a sensitive hydrogen peroxide colorimetric sensor based on the redox-mediated chromogenic reaction and depicted the application both in detection of enzyme and in an immunoassay. Combining the traditional chromogenic reagent with gold nanoparticles, our assay has the advantage in short response time (within three minutes), high sensitivity (10(-12) g mL(-1) for HBsAg) and stability. PMID:27506364

  7. Quality improvement in the care of live liver donors: implementation of the Designated Donor Nurse Program.

    PubMed

    LaPointe Rudow, Dianne; Cabello, Charlotte C; Rivellini, Denise

    2010-12-01

    Publications on living donor liver transplant have focused on the medical aspects of donor selection, postoperative management, surgical procedures, and outcomes, but little attention has been given to the nursing implications for care of live liver donors during their inpatient stay. Donor advocates from various disciplines are involved during the initial education and evaluation, but most care after surgery is delivered by an inpatient medical team and bedside nursing staff who are not as familiar with the donor and concepts related to donor advocacy. In an effort to improve the overall donor experience and provide safe, high-quality care to patients undergoing elective partial hepatectomy, our academic medical center began a quality improvement project focused on improving the inpatient stay. Inpatient nursing standards and policies and procedures were developed to ensure that consistent care is delivered. However, the infrequency of living donor liver transplantation makes it nearly impossible to have all transplant program staff on a nursing unit be "experts" on donor care. Therefore, our center determined that, similar to the Independent Donor Advocacy Team, a transplant program needs live donor champions on the nursing unit to mirror the goals of the team. To that end, we developed the concept of the Designated Donor Nurse to care for and advocate for live liver donors during the inpatient stay and also to serve as a resource to their colleagues. PMID:21265291

  8. The living donor advocate: a team approach to educate, evaluate, and manage donors across the continuum.

    PubMed

    Rudow, Dianne LaPointe

    2009-03-01

    Living donor transplant has developed as a direct result of the critical shortage of deceased donors. Federal regulations require transplant programs to appoint an independent donor advocate to ensure safe evaluation and care of live donors. Ethical and pragmatic issues surround the donor advocate. These issues include the composition of a team versus an individual advocate, who appoints them, and the role that the advocate(s) play in the process. A team approach to donor advocacy is recommended. Common goals of the independent donor advocacy team should be protocol development, education, medical and psychosocial evaluation, advocacy, support, and documentation throughout the donation process. The team's involvement should not end with consent and donation but should continue through short- and long-term follow-up and management. Ultimately it is the goal of the independent donor advocacy team to assist donors to advocate for themselves. Once deemed medically and psychologically suitable, donors must determine for themselves what they wish to do and must be free to vocalize this to their team. The decision to donate or not affects the donor first. Optimal outcomes begin with prepared, educated, uncoerced, and motivated donors, and it is the team's goal to help donors reach this point. PMID:19341065

  9. Automated homogeneous immunoassay analysis of cotinine in urine.

    PubMed

    Niedbala, R Sam; Haley, Nancy; Kardos, Stephanie; Kardos, Keith

    2002-04-01

    A study was conducted to evaluate the performance comparison of a homogeneous enzyme immunoassay (EIA) designed to detect cotinine in urine and carbon monoxide (CO) breath measurements to determine smoking status. The clinical comparison was done using urine and breath specimens from 218 volunteers. Urine samples were analyzed by immunoassay and confirmed by gas chromatography-mass spectrometry (GC-MS). Breath carbon monoxide was determined by a commercial analyzer. Using cutoffs of 10 ppm for CO and 500 ng/mL for urinary cotinine, the relative sensitivity/specificity was 93.6%/74.0%. The positive predictive value was 86.8%, and the negative predictive value was 86.5%. However, comparison of the EIA to GC-MS showed a sensitivity/specificity of 96.2%/98.4% and a positive predictive value of 99.3%. The EIA was also evaluated non-clinically for precision, stability, recovery, and interferences. In addition, the non-clinical evaluation demonstrated coefficients of variation from 0.37 to 1.09% across cotinine concentrations ranging from 0 to 5000 ng/mL. The assay was found to be highly specific for cotinine and cross-reacted to a limited degree with 3-hydroxycotinine. Finally, multiple freeze-thaw cycles of urines containing cotinine showed no degradation of the drug in the specimen when tested in the EIA. Thus, the EIA tested is a rapid, lab-based test that can reliably determine cotinine levels and their relation to smoking status. PMID:11991533

  10. Development of immunoassays for biomonitoring of hexamethylene diisocyanate exposure.

    PubMed Central

    Lemus, R; Lukinskeine, L; Bier, M E; Wisnewski, A V; Redlich, C A; Karol, M H

    2001-01-01

    Hexamethylene diisocyanate (HDI) is used widely to manufacture polyurethanes for paints and coatings. It is an irritant and a chemical asthmagen. The U.S. Occupational Safety and Health Administration time-weighted average permissible exposure limit is 5 ppb and the ceiling limit is 20 ppb. We sought to develop a sensitive and specific immuno-bioassay to supplement workplace air monitoring and detect recent HDI exposure. For this, we produced rabbit antiserum to HDI-adducted keyhole limpet hemocyanin (HDI-KLH). The specificity of the antiserum was demonstrated by its reaction with a variety of HDI-conjugated proteins and the absence of reactions with conjugates of other diisocyanates, namely toluene diisocyanate and diphenyl methylene diisocyanate. Four immunoassays were developed and compared for their ability to detect decreasing quantities of HDI-adducted human serum albumin (HSA) containing 2 mol HDI adduct per mol HSA (HDI(2)-HSA) as determined by matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry. The sensitivities of some of the assays are within the range (0.82-45 nM) of current analytic methods. A Western analysis procedure has a sensitivity of 600 nM HDI adduct on HSA. ELISA inhibition assay, in which microtiter plates are coated with the HDI(2)-HSA antigen, has a sensitivity of 300 nM HDI adduct. An immunoblot assay has a sensitivity of 9 nM HDI adduct. The most sensitive bioassay (1.8 nM HDI adduct) is a three-antibody sandwich ELISA in which wells of microtiter plates are coated with the IgG fraction of the anti-HDI-KLH antisera. Compared with analytic methods for HDI biomonitoring, the immunoassays are faster and less costly and accommodate numerous samples simultaneously. The assays have the potential to affect industrial biomonitoring programs significantly. PMID:11712993

  11. Fluorescence immunoassay for detecting periodontal bacterial pathogens in plaque.

    PubMed Central

    Wolff, L F; Anderson, L; Sandberg, G P; Aeppli, D M; Shelburne, C E

    1991-01-01

    A particle concentration fluorescence immunoassay has been modified into a bacterial concentration fluorescence immunoassay (BCFIA) to rapidly detect periodontopathic bacteria in human plaque samples. The BCFIA utilizes fluorescently tagged monoclonal antibodies (MAbs) directed against the lipopolysaccharide of selected gram-negative plaque bacteria. Microorganisms closely associated with periodontal disease that can be identified in plaque with the BCFIA include Porphyromonas gingivalis, Bacteroides intermedius, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Eikenella corrodens. Briefly, the procedure involved mixing a patient's plaque sample or other bacterial preparation with a species-specific fluorescein isothiocyanate-labeled MAb in a specialized microtiter plate. This mixture was incubated to allow binding of the MAb to its homologous bacteria. The bound and unbound fluorescent tagged MAbs were separated by filtration in the modified microtiter plate, and the total bacterial bound fluorescence was determined with a fluorimeter. The number of a specific bacterial species in a given plaque sample or other bacterial suspension was estimated by reference to a primary standard carried through the BCFIA. The lower detection limit of the BCFIA was 10(3) to 10(4) bacterial cells from single cultures of bacteria or 10(4) bacterial cells in mixed cultures. The coefficient of variation within and between plates for each of the five bacterium-specific MAbs in screening plaque for the periodontal pathogens was less than 10%. These results demonstrate that microbes in plaque can be used as the solid phase in the BCFIA to detect and quantitate MAbs associated with specific bacteria quickly and reliably. PMID:1761686

  12. The development of immunoassays for detection of chemical warfare agents

    SciTech Connect

    Lenz, D.E.; Brimfield, A.A.; Cook, L.

    1996-10-01

    With the advent of enzyme linked immunoabsorbent assays (ELISA) and monoclonal antibodies in the last two decades, there has been considerable effort devoted to the development of antibodies to detect and quantify low molecular weight toxic substances in environmental or biological fluids. Polyclonal antibodies against paraoxon (the toxic metabolite of parathion) were capable of detecting paraoxon in body fluids at a level of 10{sup -9} M ({approximately}260 pg/mL) when used in a competitive inhibition enzyme immunoassay (CIEIA). Monoclonal antibodies developed against a structural analogue of the chemical warfare agent soman were capable of detection soman in buffer solutions at a level of 10{sup -6} M ({approximately}180 ng/mL). In addition these antibodies were found to be highly specific for soman even in the presence of its major hydrolysis product. Subsequent studies with antisoman monoclonal antibodies extended the level of sensitivity to {approximately}80 ng/mL. Furthermore these antibodies did not cross react with other chemical warfare nerve agents such as sarin or tabun. In all cases, the time for a confirmatory test was two hours or less. Immunoassays for T-2 micotoxins have also been reported with a minimal detection range of 2 pg/assay to 50 ng/assay for the polyclonal and monoclonal T-2 antibodies respectively. These reagents offer a sensitive, rapid and low cost approach to the diagnosis or detection of the presence of toxic chemical substances. More recent efforts have focussed on developing antibodies specific for sulfur mustard a highly reactive vesicating agent.

  13. Management of the inpatient canine blood donor.

    PubMed

    Hohenhaus, A E

    1992-12-01

    The availability of inpatient blood donors as a source for transfusion allows flexibility that is lacking in an outpatient program. Choosing the appropriate dog as a donor is essential to the success of a hospital blood bank. Once a dog becomes a blood donor, routine physical and clinicopathologic examinations are necessary to monitor the animal's health and to ensure the quality of blood products. PMID:1472767

  14. Living-donor liver transplantation: current perspective.

    PubMed

    Lobritto, Steven; Kato, Tomoaki; Emond, Jean

    2012-11-01

    The disparity between the number of available deceased liver donors and the number of patients awaiting transplantation continues to be an ongoing issue predisposing to death on the liver transplant waiting list. Deceased donor shortage strategies including the use of extended donor-criteria deceased donor grafts, split liver transplants, and organs harvested after cardiac death have fallen short of organ demand. Efforts to raise donor awareness are ongoing, but the course has been arduous to date. Living donor transplantation is a means to access an unlimited donor organ supply and offers potential advantages to deceased donation. Donor safety remains paramount demanding improvements and innovations in both the donor and recipient operations to ensure superior outcomes. The specialty operation is best preformed at centers with specific expertise and shuttling of select patients to these centers supported by third party payers is critical. Training future surgeons at centers with this specific experience can help disseminate this technology to improve local availability. Ongoing research in immunosuppression minimization, withdrawal and tolerance induction may make living donation a desired first-line operation rather than a necessary albeit less-desirable option. This chapter summarizes the progress of living liver donation and its potential applications. PMID:23397534

  15. Living kidney donor experiences: implications for counselling.

    PubMed

    Walsh, A

    2004-01-01

    This study adds to previous, mostly quantitative, investigation into the experiences of living related kidney donors. Such investigation is important so that potential donors are supported effectively and donation programmes remain relevant and specific to need. Exploration takes place into donor decision-making processes and the most effective forms of professional support. A non-probability sampling technique highlighted eight living related kidney donors who were interviewed using a semi-structured interview format. Raw data was analysed through the qualitative technique of Interpretative Phenomenological Analysis. The decision to donate is made rapidly, decisively and rationally. Professional support provides reassurance to donors, particularly when experiencing acute psychological reaction. The need to provide support to the parents of living donors is specifically highlighted. A comprehensive range of Master Themes are generated through Interpretative Phenomenological Analysis and these reflect the complexity of the donation experience. This suggests donors are concerned with the management of psychological experience rather than with reviewing the appropriateness of an original decision to donate. Evidence indicates that concepts of attitude and self-efficacy belief can develop understanding of the psychological experience of being a living kidney donor. A counselling perspective, with Social Cognitive Theory at its core, is highlighted as a valid method for providing professional support to donors before and after surgery. PMID:15835410

  16. [Kidney transplant from living donors in children?].

    PubMed

    Ginevri, Fabrizio; Dello Strologo, Luca; Guzzo, Isabella; Belingheri, Mirco; Ghio, Luciana

    2011-01-01

    A living-donor kidney transplant offers a child at the terminal stages of renal disease better functional recovery and quality of life than an organ from a deceased donor. Before starting the procedure for a living-donor transplant, however, it is necessary to establish if it is really safe. There are diseases, such as focal segmental glomerulosclerosis, atypical HUS and membranoproliferative glomerulonephritis with dense deposits, for which living donation is not recommended given the high incidence of recurrence of the disease but also the frequent loss of the graft. Regarding the selection of the donor, an increased risk of acute rejection has been reported for donors older than 60-65 years and a worsening of the renal outcome if the donor's weight is equal to or less than the recipient's. Finally, it is necessary to take into consideration that complications may arise in the donor both in the perioperative period and in the long term. In conclusion, kidney transplant from a living donor is a natural choice within the pediatric setting. The parents, usually young and highly motivated to donate, are the ideal donors. However, although the risks associated with donation are minimal, they are not totally absent, and consequently it is mandatory to follow standardized procedures according to the guidelines issued by the Centro Nazionale Trapianti. PMID:21341241

  17. DGTI Register of Rare Donors

    PubMed Central

    Hustinx, Hein

    2014-01-01

    Summary For patients with antibodies against the most common blood groups a rapid and efficient supply of compatible erythrocyte concentrates is self-evident. But typically we have to make the greatest effort providing blood for these patients, which have made antibodies against common blood groups. There are however patients with antibodies against rare blood group antigens that need special blood. The supply of such blood can be very difficult and mostly time-consuming. For this reason we set up a database of blood donors with rare blood groups. Since 2005 the BTS SRC Berne Ltd. has run this database on behalf of the Swiss BTS SRC. After a reorganization and extension of the database, conducted during 2011/2012, the data file was renamed ‘DGTI Register of Rare Donors’ and is now run under the patronage of the German Society for Transfusion Medicine and Immunohematology (DGTI). PMID:25538534

  18. [Liver transplants from living donors].

    PubMed

    Rogiers, X; Danninger, F; Malagó, M; Knoefel, W T; Gundlach, M; Bassas, A; Burdelski, M; Broelsch, C E

    1996-03-01

    In this article the authors discuss the advantages of Living Related Liver Transplantation (LRLT), criteria for the selection of donors and the standard operation technique. Among a total of 241 liver transplantation (LTx), 42 LRLT were performed at the University of Hamburg between October 1, 1991 and December 19, 1994. The body weight of recipients for LRLT ranged from 4,6 to 39 kg, with 64,2% having less than 10 kg. The volume of the donor left lateral liver lobe ranged from 100 cc to 350 cc. The average one year survival rate among electively operated patients-status 3-4 (UNOS 1995 classification) was 86.7%, two year survival rate 83.3%. The main advantages of LRLT are consired the following: 1. Absence of mortality on the waiting list, 2. Optimal timing of the transplantation (elective procedure, patient in a good condition), 3. Excellent organ (no primary non function), 4. A possible immunologic advantage, 5. Relief of the waiting list for cadaveric organs, 6. Psychological benefit for the family, 7. Cost effectiveness. Potential candidates for living donation with more than one cardiovascular risk factors were excluded. Social and psychological reasons leading to rejection of candidates were as follows: unstable family structure, expected professional or financial difficulties after living donation or withdrawal from consent. LRLT gives parents of a child with TLD a chance to avoid the risk of death on the waiting list or primary non function of the graft. LRLT has therefore established an important place in pediatric liver transplantation. PMID:8768973

  19. Polarization of human donor corneas.

    PubMed

    Parekh, Mohit; Ruzza, Alessandro; Ferrari, Stefano; Salvalaio, Gianni; Elbadawy, Hossein; Ponzin, Diego; Lipari, Eugenio

    2016-06-01

    To investigate the de-orientation effect of DSAEK grafts by observing the cross patterns and polarization power of human donor corneas using a polarizing device (Lumaxis(®)). Forty human donor corneas were placed in small petri-plates with epithelial side facing up. Polarizing power (arbitrary unit) and crosses were monitored and recorded by the software. The tissue was marked at 'Superior' position to ensure that the base and the polarizer are in alignment with each other after the cut. The anterior lamellar cut was performed using microkeratome. The lenticule was placed back in the same position as marked to mimic the alignment. The tissue was further rotated by 45° ensuring that the base of the cornea and the polarizer were in alignment. The polarization power and 'crosses' were identified at each step. The average of forty corneas from pre-cut to post-45° angular change showed statistically significant difference (p < 0.05) in terms of polarizing power. The cross-shaped pattern deformed and lost the sharpness towards 45° angle. However, multiple variances in terms of 'cross-patterns' were observed throughout the study. Lumaxis(®) was able to determine the worst quality tissue in terms of polarization (no black zone and crosses). Despite the quality of cross pattern which can be used as an additional objective parameter to evaluate the optical properties of the corneal tissue, this preliminary study needs to be further justified in terms of clinical relevance whether polarization changes with oriented or de-oriented grafts have any effects and consequences on the visual acuity. PMID:26920874

  20. An Inexpensive, Fast and Sensitive Quantitative Lateral Flow Magneto-Immunoassay for Total Prostate Specific Antigen

    PubMed Central

    Barnett, Jacqueline M.; Wraith, Patrick; Kiely, Janice; Persad, Raj; Hurley, Katrina; Hawkins, Peter; Luxton, Richard

    2014-01-01

    We describe the detection characteristics of a device the Resonant Coil Magnetometer (RCM) to quantify paramagnetic particles (PMPs) in immunochromatographic (lateral flow) assays. Lateral flow assays were developed using PMPs for the measurement of total prostate specific antigen (PSA) in serum samples. A detection limit of 0.8 ng/mL was achieved for total PSA using the RCM and is at clinically significant concentrations. Comparison of data obtained in a pilot study from the analysis of serum samples with commercially available immunoassays shows good agreement. The development of a quantitative magneto-immunoassay in lateral flow format for total PSA suggests the potential of the RCM to operate with many immunoassay formats. The RCM has the potential to be modified to quantify multiple analytes in this format. This research shows promise for the development of an inexpensive device capable of quantifying multiple analytes at the point-of-care using a magneto-immunoassay in lateral flow format. PMID:25587419

  1. Dynamic light scattering (DLS)-based immunoassay for ultra-sensitive detection of tumor marker protein.

    PubMed

    Li, Chao; Ma, Jiehua; Fan, Qiongxuan; Tao, Yaqin; Li, Genxi

    2016-06-14

    A novel dynamic light scattering (DLS)-based immunoassay that utilizes manganese dioxide nanosheet-modified gold nanoparticles (MnO2-GNPs) as an activatable nanoprobe has been developed to detect tumor markers down to femtomolar levels. PMID:27247980

  2. A sensitive rapid on-site immunoassay for heavy metal contamination

    SciTech Connect

    Blake, R.; Blake, D.; Flowers, G.

    1996-05-02

    This project concerns the development of immunoassays for heavy metals that will permit the rapid on-site analysis of specific heavy metals, including lead and chromium in water and soil samples. 2 refs.

  3. Performance evaluation of the phosphorescent porphyrin label: solid-phase immunoassay of alpha-fetoprotein.

    PubMed

    O'Riordan, Tomás C; Soini, Aleksi E; Soini, Juhani T; Papkovsky, Dmitri B

    2002-11-15

    Phosphorescent conjugates of antibodies, neutravidin, and biotin (pentylamine derivative) were synthesized using previously described monofunctional labeling reagent of platinum(II) coproporphyrin-I with isothiocyanate reactive group (PtCP-NCS). These conjugates, which can be considered as standard reagents for a range of bioanalytical applications, were evaluated in solid-phase immunoassay schemes with the clinical analyte a-fetoprotein (AFP). A custom-designed time-resolved phosphorescence plate reader based on a compact and low-cost 532-nm laser and optimized for measurement of porphyrin labels was used. Using optimized tracers, instrumentation and assay protocols, subpicomolar detection limits were obtained both for PtCP label in solution and for AFP in solid-phase immunoassay. This sensitivity is comparable with standard time-resolved fluorescence immunoassays with lanthanide labels. The performance of metalloporphyrin labels, instrumentation, and solid-phase immunoassays as an alternative to the established detection platforms is discussed. PMID:12463371

  4. Enzyme immunoassay-based survey of prevalence of gentamicin in serum of marketed swine.

    PubMed

    Berkowitz, D B; Webert, D W

    1986-01-01

    Sera from 3182 swine from a national sampling were tested in the gentamicin enzyme immunoassay. Of the sera tested, 6 (0.19%) contained gentamicin. Only 1 serum may have been associated with muscle levels above the tolerance. During the survey, a single analyst processed 300 samples daily. The immunoassay survey was an effective and economical method of obtaining information on the prevalence of a residue. PMID:3522536

  5. The Experience of Living Kidney Donors

    ERIC Educational Resources Information Center

    Brown, Judith Belle; Karley, Mary Lou; Boudville, Neil; Bullas, Ruth; Garg, Amit X.; Muirhead, Norman

    2008-01-01

    This article describes the experiences, feelings, and ideas of living kidney donors. Using a phenomenological, qualitative research approach, the authors interviewed 12 purposefully selected living kidney donors (eight men and four women), who were between four and 29 years since donation. Interviews were audiotaped, and transcribed verbatim, and…

  6. The value of living donor liver transplantation.

    PubMed

    Yang, Xiaoli; Gong, Junhua; Gong, JianPing

    2012-12-31

    Living donor liver transplantation (LDLT) is a very successful procedure that develops liver resources in case of worldwide shortages. As the technology has developed so much in the past 2 decades, LDLT has the same good prognosis as DDLT. However, LDLT still has lots of ethical & technical problems. It causes great psychiatric, physical and psychosocial harm to donors. Also, it has some negative effects on society by providing a platform for organ trade. Therefore, there is much controversy about the social value of LDLT. After review of recent papers, we find much progress can be made in inspiring the public to become organ donors and creating donation model new to improve the consent rate for solid organ donation from deceased donors. That is the key strategy for increasing the liver supply. With this serious shortage of organs, liver donor transplantation still has its advantages, but we should not place all our hopes on LDLT to increase the liver supply. We all need to try our best to increase donor awareness and promote organ donor registration--when cadaver organs could meet the needs for liver transplantation, living donor liver transplants would not be necessary. PMID:23274332

  7. Payment for donor kidneys: pros and cons.

    PubMed

    Friedman, E A; Friedman, A L

    2006-03-01

    Continuous growth of the end stage renal disease population treated by dialysis, outpaces deceased donor kidneys available, lengthens the waiting time for a deceased donor transplant. As estimated by the United States Department of Health & Human Services: '17 people die each day waiting for transplants that can't take place because of the shortage of donated organs.' Strategies to expand the donor pool--public relations campaigns and Drivers' license designation--have been mainly unsuccessful. Although illegal in most nations, and viewed as unethical by professional medical organizations, the voluntary sale of purchased donor kidneys now accounts for thousands of black market transplants. The case for legalizing kidney purchase hinges on the key premise that individuals are entitled to control of their body parts even to the point of inducing risk of life. One approach to expanding the pool of kidney donors is to legalize payment of a fair market price of about 40,000 dollars to donors. Establishing a federal agency to manage marketing and purchase of donor kidneys in collaboration with the United Network for Organ Sharing might be financially self-sustaining as reduction in costs of dialysis balances the expense of payment to donors. PMID:16482095

  8. 42 CFR 35.64 - Donors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Donors. 35.64 Section 35.64 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Contributions for the Benefit of Patients § 35.64 Donors. Authorized contributions...

  9. 42 CFR 35.64 - Donors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Donors. 35.64 Section 35.64 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Contributions for the Benefit of Patients § 35.64 Donors. Authorized contributions...

  10. 42 CFR 35.64 - Donors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Donors. 35.64 Section 35.64 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Contributions for the Benefit of Patients § 35.64 Donors. Authorized contributions...

  11. Recipients' views on payment of sperm donors.

    PubMed

    Ravelingien, An; Provoost, Veerle; Wyverkens, Elia; Buysse, Ann; De Sutter, Petra; Pennings, Guido

    2015-08-01

    The aim of this qualitative study was to explore how recipients viewed payment of sperm donors. The study was conducted in Belgium, where, as in many countries, sperm donors receive recompense for their time and expenses. Face-to-face semi-structured interviews were conducted with 34 heterosexual and lesbian couples who, at the time of data collection, had at least one donor-conceived child aged 7-10 years or who were undergoing donor conception treatment. Although participants commonly described the issue of financial compensation as something that did not really concern them, all supported the idea that some level of payment was acceptable or even necessary. The participants also identified several ways in which donor payment offered advantages to their own position as (future) parents. Although the idea is commonly rehearsed that sperm donation is a gift and that monetary transaction for conception is demeaning, the participants of this study did not generally share this view. To them, a small financial return served as a symbolic acknowledgement of the donor's contribution and helped secure the type of relationship they expected from their donor. There was clearly concern, however, over high payments and the risk of attracting the wrong kind of donor. PMID:26099446

  12. Negotiating boundaries: Accessing donor gametes in India

    PubMed Central

    Widge, A.; Cleland, J.

    2011-01-01

    Background: This paper documents how couples and providers access donor materials for conception in the Indian context and perceptions about using them. The objective is to facilitate understanding of critical issues and relevant concerns. Methods: A postal survey was conducted with a sample of 6000 gynaecologists and in-depth interviews were conducted with 39 gynaecologists in four cities. Results: Donor gametes are relatively more acceptable than a few years ago, especially if confidentiality can be maintained, though lack of availability of donor materials is sometimes an impediment to infertility treatment. Donor sperms are usually accessed from in-house or commercial sperm banks, pathology laboratories, IVF centres, professional donors, relatives or friends. There is scepticism about screening procedures of sperm banks. Donor eggs are usually accessed from voluntary donors, friends, relatives, egg sharing programmes, donation from other patients, advertising and commercial donors. There are several concerns regarding informed consent for using donated gametes, using relatives and friends gametes, the unregulated use of gametes and embryos, record keeping and documentation, unethical and corrupt practices and commercialisation. Conclusion: These issues need to be addressed by patients, providers and regulatory authorities by providing information, counselling, ensuring informed consent, addressing exploitation and commercialisation, ensuring monitoring, proper documentation and transparency. PMID:24753849

  13. Anti-HCV immunoassays based on a multiepitope antigen and fluorescent lanthanide chelate reporters.

    PubMed

    Salminen, Teppo; Juntunen, Etvi; Khanna, Navin; Pettersson, Kim; Talha, Sheikh M

    2016-02-01

    There is a need for simple to produce immunoassays for hepatitis C virus (HCV) antibody capable of detecting all genotypes worldwide. Current commonly used third generation immunoassays use three to six separate recombinant proteins or synthetic peptides. We have developed and expressed in Escherichia coli a single recombinant antigen incorporating epitopes from different HCV proteins. This multiepitope protein (MEP) was used to develop two types of HCV antibody immunoassays: a traditional antibody immunoassay using a labeled secondary antibody (indirect assay) and a double-antigen assay with the same MEP used as capture binder and labeled binder. The secondary antibody assay was evaluated with 171 serum/plasma samples and double-antigen assay with 148 samples. These samples included an in-house patient sample panel, two panels of samples with different HCV genotypes and a seroconversion panel. The secondary antibody immunoassay showed 95.6% sensitivity and 100% specificity while the double-antigen assay showed 91.4% sensitivity and 100% specificity. Both assays detected samples from all six HCV genotypes. The results showed that combining a low-cost recombinant MEP binder antigen with a high sensitivity fluorescent lanthanide reporter can provide a sensitive and specific immunoassay for HCV serology. The results also showed that the sensitivity of HCV double-antigen assays may suffer from the low avidity immune response of acute infections. PMID:26615808

  14. Chylous ascites secondary to laparoscopic donor nephrectomy.

    PubMed

    Shafizadeh, Stephen F; Daily, Patrick P; Baliga, Prabhakar; Rogers, Jeffrey; Baillie, G Mark; Rajagopolan, P R; Chavin, Kenneth D

    2002-08-01

    Live donor renal transplantation offers many significant advantages over cadaveric donor transplantation. Yet living donation continues to be underused, accounting for less than 30% of all donor renal transplants. In an attempt to remove the disincentives to live donation, Ratner et al. developed laparoscopic donor nephrectomy (LDN). LDN is gaining acceptance in the transplant community. The overriding concern must always be the safety and welfare of the donor. To this end, potential complications of LDN must be identified and discussed. We present a patient who developed the complication of chylous ascites from LDN. To improve the laparoscopic technique further, a discussion of its successes and complications needs to be encouraged. To this end, we present chylous ascites as a potential complication after LDN. We also offer suggestions to minimize the likelihood of this complication. PMID:12137847

  15. Non Heart-Beating Donors in England

    PubMed Central

    Chaib, Eleazar

    2008-01-01

    When transplantation started all organs were retrieved from patients immediately after cardio-respiratory arrest, i.e. from non-heart-beating donors. After the recognition that death resulted from irreversible damage to the brainstem, organ retrieval rapidly switched to patients certified dead after brainstem testing. These heart-beating-donors have become the principal source of organs for transplantation for the last 30 years. The number of heart-beating-donors are declining and this is likely to continue, therefore cadaveric organs from non-heart-beating donor offers a large potential of resources for organ transplantation. The aim of this study is to examine clinical outcomes of non-heart-beating donors in the past 10 years in the UK as an way of decreasing pressure in the huge waiting list for organs transplantation. PMID:18297216

  16. Kinetics of thermal donor generation in silicon

    NASA Technical Reports Server (NTRS)

    Mao, B.-Y.; Lagowski, J.; Gatos, H. C.

    1984-01-01

    The generation kinetics of thermal donors at 450 C in Czochralski-grown silicon was found to be altered by high-temperature preannealing (e.g., 1100 C for 30 min). Thus, when compared with as-grown Si, high-temperature preannealed material exhibits a smaller concentration of generated thermal donors and a faster thermal donor saturation. A unified mechanism of nucleation and oxygen diffusion-controlled growth (based on solid-state plate transformation theory) is proposed to account for generation kinetics of thermal donors at 450 C, in as-grown and high-temperature preannealed Czochralski silicon crystals. This mechanism is consistent with the main features of the models which have been proposed to explain the formation of oxygen thermal donors in silicon.

  17. Evaluation of Iron Store by Serum Ferritin in Healthy Blood Donors of Bangladesh.

    PubMed

    Hoque, M M; Adnan, S D; Karim, S; Mamun, M A; Nandy, S; Faruki, M A; Islam, K

    2016-07-01

    Iron stores in the body exist primarily in the form of ferritin. Small amounts of ferritin secreted into the plasma and plasma ferritin is positively correlated with the size of the total body iron stores. The present study conducted to determine the iron status using the serum ferritin level among healthy Bangladeshi blood donors. The present cross sectional study was conducted in the Department of Transfusion Medicine, Dhaka Medical College, Dhaka, Bangladesh from July 2011 to June 2012. Blood donor signed informed consent and has satisfactory pre-donation health assessment and satisfactory post-donation blood test results were included in the study. Full blood counts were performed within 4 hours of collection using an automated haematology analyzer. Serum ferritin was measured using a validated enzyme immunoassay. Data were analyzed using SPSS version 16 (SPPS Incorporation, Chicago, IL, USA). P value <0.05 was considered as statistically significant. Total 100 blood donors were included in the study, among them 88 were male and 12 were female. Mean±SD of the age of the respondents was 26.8±5.9 years with a range of 19 to 45 years. Mean±SD of heamoglobin level (gm/dl) and total count of Red Blood Cell (million/cmm) were 14.1±1.4 and 5.1±0.4 respectively. Mean±SD of serum ferritin level (ng/ml) was 96.4±69.0ng/ml with a range of 4.1ng/ml to 298.7ng/ml. Among the respondents 9.0% had depleted iron store, 7.0 reduced iron store and 84.0% had normal iron store. Among the respondents 5.0% had iron deficiency anaemia in term of serum ferritin level. Statistically significant difference of serum ferritin level observed between male and female and donors with and without history of previous blood donation. Among the healthy blood donors of Bangladesh abnormal serum ferritin is highly prevalent among blood donors specially among female. Monitoring of iron stores by serum ferritin seems justified in order to identify those with depleted iron stores who will

  18. Analysis of Plasma Cytokine and Chemokine Profiles in Patients with and without Tuberculosis by Liquid Array-Based Multiplexed Immunoassays

    PubMed Central

    Wang, Juanjuan; Zou, Xiaoming; Wen, Qian; Luo, Wei; Liu, Sudong; He, Jianchun; Cai, Shaoxi; Ma, Li

    2016-01-01

    The aim of this study was to establish plasma cytokine/chemokine profiles in patients with 3 different presentations of active tuberculosis (TB), compared to the profiles observed in bacillus Calmette-Guérin (BCG)-vaccinated healthy individuals and patients with other pulmonary diseases (non-TB patients). To this end, plasma samples were collected from 151 TB patients including 68 pulmonary TB (PTB), 43 endobronchial TB, and 40 tuberculosis pleurisy (TP) patients, as well as 107 no-TB cases including 26 non-TB patients and 81 BCG-vaccinated healthy controls. A liquid array-based multiplexed immunoassay was used to screen plasma samples for 20 distinct cytokines and chemokines. Multinomial logistic regression was used to analyze associations between cytokines/chemokines and TB/non-TB patients. Compared to our findings with the no-TB donors, the median plasma levels of the proinflammatory cytokines/chemokines TNF-α, IL-6, IP-10, IFN-γ, and MIP-1β were significantly elevated in TB patients, suggesting their potential use as biomarkers for diagnosing TB patients. Further comparisons with healthy donors showed that only the median TNF-α plasma level was highly produced in the plasma of all 3 types of TB patients. Plasma IL-6 production was higher only in TP patients, while the plasma levels of IP-10, IFN-γ, and MIP-1β were markedly enhanced in both PTB and TP patients. Unexpectedly, among the above cytokines/chemokines, MIP-1β was also highly expressed in non-TB patients, compared with healthy donors. Our results suggested that TNF-α may be an ideal biomarker for diagnosing the 3 forms of TB presentation, while the other factors (IL-6, IP-10, MCP-1, and IFN-γ) can potentially facilitate differential diagnosis for the 3 TB presentation types. Further characterization of immune responses associated with different types of TB diseases will provide a basis for developing novel TB diagnostics. PMID:26881918

  19. The impact of the donors' and recipients' medical complications on living kidney donors' mental health.

    PubMed

    Timmerman, Lotte; Laging, Mirjam; Timman, Reinier; Zuidema, Willij C; Beck, Denise K; IJzermans, Jan N M; Betjes, Michiel G H; Busschbach, Jan J V; Weimar, Willem; Massey, Emma K

    2016-05-01

    A minority of living kidney donors (between 5-25%) have poor psychological outcomes after donation. There is mixed evidence on the influence of medical complications on these outcomes. We examined whether medical complications among donors and recipients predicted changes in donors' mental health (psychological symptoms and well-being) between predonation and 1 year postdonation. One-hundred and forty-five donors completed questionnaires on mental health predonation and 3 and 12 months postdonation. Number of recipient rehospitalizations and donor complications (none; minor; or severe) were obtained from medical records at 3 and 12 months after surgery. Multilevel regression analyses were used to examine the association between medical complications and changes in donors' mental health over time after controlling for sociodemographic characteristics. We found that donor complications (P = 0.003) and recipient rehospitalizations (P = 0.001) predicted an increase in donors' psychological symptoms over time. Recipient rehospitalizations also predicted a decrease in well-being (P = 0.005) over time; however, this relationship became weaker over time. We conclude that medical complications experienced by either the donor or recipient is a risk factor for deterioration in donors' mental health after living kidney donation. Professionals should monitor donors who experience medical complications and offer additional psychological support when needed. PMID:26895841

  20. Blood donors screening for malaria in non-endemic area in the Kingdom of Saudi Arabia: Is it necessary to introduce immunological testing?

    PubMed Central

    Elyamany, Ghaleb; Al Gharawi, Ali; Alrasheed, Mohammed; Alsuhaibani, Omar

    2016-01-01

    Introduction In Saudi Arabia, where malaria is not endemic, the incidence is very low. However, malaria transmission cases have been reported, mainly in Asir and Jazan provinces along the Southwestern border with Yemen. Imported cases also have been reported. The aims of this study were to determine the prevalence of malaria in blood donors in a tertiary care hospital in the central area of Saudi Arabia and to assess the effectiveness of malaria screening methods used by transfusion services in Prince Sultan Military Medical City. Methods This study was conducted on 180,000 people who donated blood during 2006–2015. All blood smears from blood donors were screened for malaria infection using Giemsa staining, low power and high power microscopic examinations, and using oil immersion lens. The data were analyzed and reported in descriptive statistics and prevalence. Results From the total of 180,000 blood donors who were screened for malaria, 156,000 (87%) and 23.400 (13%) were Saudi Arabia citizens and non-Saudi residents, respectively. The mean age of the blood donors was 32 (ranging from 18 to 65), 97% and 3% were male and female, respectively. Using our current method for malaria screening, the prevalence of malaria in the study population was zero. Conclusion The current methods of malaria screening in blood donors is not suitable for screening low-level parasiotemia. Adding the immunoassay and molecular screening methods is suggested. PMID:27054011

  1. A magnetite suspension-based washing method for immunoassays using Escherichia coli cells with autodisplayed Z-domains.

    PubMed

    Kim, Do-Hoon; Bong, Ji-Hong; Yoo, Gu; Chang, Seo-Yoon; Chang, Young Wook; Kang, Min-Jung; Jose, Joachim; Pyun, Jae-Chul

    2016-10-01

    Escherichia coli cells with autodisplayed Z-domains have been used for immunoassays of specific target analytes. In this study, a magnetite suspension was used for the washing step in immunoassays of E. coli cells with autodisplayed Z-domains. This approach enhanced the washing conditions for these immunoassays by determining (1) the optimal concentration of the magnetite suspension, (2) the capacity of the magnetite suspension-based washing method to recover E. coli cells, and (3) the level at which the activity of autodisplayed Z-domains is maintained. In immunoassays of C-reactive protein (CRP), the immunoassay incorporating the magnetite suspension-based washing method showed a sensitivity and limit of detection considerably higher than those of the conventional centrifugation-based washing method. The results indicated that immunoassays incorporating the magnetite suspension-based washing method are effective for medical diagnoses based on CRP assay. PMID:27542738

  2. Oocyte cryopreservation for donor egg banking.

    PubMed

    Cobo, Ana; Remohí, José; Chang, Ching-Chien; Nagy, Zsolt Peter

    2011-09-01

    Oocyte donation is an efficient alternative to using own oocytes in IVF treatment for different indications. Unfortunately, 'traditional' (fresh) egg donations are challenged with inefficiency, difficulties of synchronization, very long waiting periods and lack of quarantine measures. Given the recent improvements in the efficiency of oocyte cryopreservation, it is reasonable to examine if egg donation through oocyte cryopreservation has merits. The objective of the current manuscript is to review existing literature on this topic and to report on the most recent outcomes from two established donor cryobank centres. Reports on egg donation using slow freezing are scarce and though results are encouraging, outcomes are not yet comparable to a fresh egg donation treatment. Vitrification on the other hand appears to provide high survival rates (90%) of donor oocytes and comparable fertilization, embryo development, implantation and pregnancy rates to traditional (fresh) egg donation. Besides the excellent outcomes, the ease of use for both donors and recipients, higher efficiency, lower cost and avoiding the problem of synchronization are all features associated with the benefit of a donor egg cryobank and makes it likely that this approach becomes the future standard of care. Oocyte donation is one of the last resorts in IVF treatment for couples challenged with infertility problems. However, traditional (fresh) egg donation, as it is performed today, is not very efficient, as typically all eggs from one donor are given to only one recipient, it is arduous as it requires an excellent synchronization between the donor and recipient and there are months or years of waiting time. Because of the development of an efficient oocyte cryopreservation technique, it is now possible to cryo-store donor (as well as non-donor) eggs, maintaining their viability and allowing their use whenever there is demand. Therefore, creating a donor oocyte cryobank would carry many advantages

  3. Liver regeneration after living donor transplant

    PubMed Central

    Olthoff, Kim M.; Emond, Jean C.; Shearon, Tempie H.; Everson, Greg; Baker, Talia B.; Fisher, Robert A.; Freise, Chris E.; Gillespie, Brenda W.; Everhart, James E.

    2014-01-01

    Background & Aims Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth and identify associated factors in a multicenter study. Methods 350 donors and 353 recipients in A2ALL (Adult to Adult Living Donor Liver Transplantation Cohort Study) transplanted between March 2003 and February 2010 were included. Potential predictors of 3-month liver volume included total and standard liver volumes (TLV, SLV), the model for end-stage liver disease (MELD) score (in recipients), remnant and graft size, remnant to donor and graft to recipient weight ratio (RDWR, GRWR), remnant/TLV, and graft/SLV. Results Among donors, 3-month absolute growth was 676±251g (mean± SD) and percent reconstitution was 80%±13%. Among recipients, GRWR was 1.3%±0.4% (8<0.8%). Graft weight was 60%±13% of SLV. Three-month absolute growth was 549±267g and percent reconstitution was 93%±18%. Predictors of greater 3-month liver volume included larger patient size (donors, recipients), larger graft volume (recipients), and larger TLV (donors). Donors with the smallest remnant/TLV ratios had larger than expected growth, but also had higher postoperative bilirubin and international normalized ratio at 7 and 30 days. In a combined donor-recipient analysis, donors had smaller 3-month liver volumes than recipients adjusted for patient size, remnant or graft volume, and TLV or SLV (p=0.004). Recipient graft failure in the first 90 days was predicted by poor graft function at day 7 (HR=4.50, p=0.001), but not by GRWR or graft fraction (p>0.90 for each). Conclusions Both donors and recipients had rapid yet incomplete restoration of tissue mass in the first 3 months, confirming previous reports. Recipients achieved a greater percentage of expected total volume. Patient size and recipient graft volume significantly influenced 3 month volumes. Importantly, donor liver volume is a critical predictor of the rate of regeneration, and donor remnant fraction impacts post

  4. Bright Solid-State Emission of Disilane-Bridged Donor-Acceptor-Donor and Acceptor-Donor-Acceptor Chromophores.

    PubMed

    Shimada, Masaki; Tsuchiya, Mizuho; Sakamoto, Ryota; Yamanoi, Yoshinori; Nishibori, Eiji; Sugimoto, Kunihisa; Nishihara, Hiroshi

    2016-02-01

    The development of disilane-bridged donor-acceptor-donor (D-Si-Si-A-Si-Si-D) and acceptor-donor-acceptor (A-Si-Si-D-Si-Si-A) compounds is described. Both types of compound showed strong emission (λem =ca. 500 and ca. 400 nm, respectively) in the solid state with high quantum yields (Φ: up to 0.85). Compound 4 exhibited aggregation-induced emission enhancement in solution. X-ray diffraction revealed that the crystal structures of 2, 4, and 12 had no intermolecular π-π interactions to suppress the nonradiative transition in the solid state. PMID:26822564

  5. Immunoassays Based on Penicillium marneffei Mp1p Derived from Pichia pastoris Expression System for Diagnosis of Penicilliosis

    PubMed Central

    Wang, Yan-Fang; Cai, Jian-Piao; Wang, Ya-Di; Dong, Hui; Hao, Wei; Jiang, Ling-Xiao; Long, Jun; Chan, Cheman; Woo, Patrick C. Y.; Lau, Susanna K. P.; Yuen, Kwok-Yung; Che, Xiao-Yan

    2011-01-01

    Background Penicillium marneffei is a dimorphic fungus endemic in Southeast Asia. It can cause fatal penicilliosis in humans, particularly in HIV-infected people. Diagnosis of this infection is difficult because its clinical manifestations are not distinctive. Specialized laboratory tests are necessary to establish a definitive diagnosis for successful management. We have demonstrated previously that a cell wall mannoprotein Mp1p, abundant in P. marneffei, is a potential biomarker for diagnosis of P. marneffei infections. In the present study, we describe immunoassays based on Mp1p derived from the yeast Pichia pastoris expression system. Methodology/Principal Findings We generated monoclonal antibodies (MAbs) and rabbit polyclonal antibodies (PAbs) against Mp1p expressed in P. pastoris. Subsequently, we developed two Mp1p antigen capture ELISAs which employed MAbs for both the capture and detecting antibodies (MAb-MAb pair) or PAbs and MAbs as the capture and detecting antibodies (PAbs-MAb pair) respectively. The two Mp1p antigen ELISAs detected Mp1p specifically in cultures of P. marneffei yeast phase at 37–40°C and had no cross-reaction with other tested pathogenic fungi. The sensitivities and specificities of the two antigen assays were found to be 55% (11/20) and 99.6% (538/540) for MAb-MAb Mp1p ELISA, and 75% (15/20) and 99.4% (537/540) for PAbs-MAb Mp1p ELISA performed using 20 sera with culture-confirmed penicilliosis, and 540 control sera from 15 other mycosis patients and 525 healthy donors. Meanwhile, we also developed an anti-Mp1p IgG antibody ELISA with an evaluated sensitivity of 30% (6/20) and a specificity of 98.5% (532/540) using the same sera. Furthermore, combining the results of Mp1p antigen and antibody detection improved the sensitivity of diagnosis to 100% (20/20). Conclusions/Significance Simultaneous detection of antigen and antibody using the immunoassays based on Mp1p derived from P. pastoris greatly improves detection sensitivity. The

  6. Donor deactivation in silicon nanostructures

    NASA Astrophysics Data System (ADS)

    Björk, Mikael T.; Schmid, Heinz; Knoch, Joachim; Riel, Heike; Riess, Walter

    2009-02-01

    The operation of electronic devices relies on the density of free charge carriers available in the semiconductor; in most semiconductor devices this density is controlled by the addition of doping atoms. As dimensions are scaled down to achieve economic and performance benefits, the presence of interfaces and materials adjacent to the semiconductor will become more important and will eventually completely determine the electronic properties of the device. To sustain further improvements in performance, novel field-effect transistor architectures, such as FinFETs and nanowire field-effect transistors, have been proposed as replacements for the planar devices used today, and also for applications in biosensing and power generation. The successful operation of such devices will depend on our ability to precisely control the location and number of active impurity atoms in the host semiconductor during the fabrication process. Here, we demonstrate that the free carrier density in semiconductor nanowires is dependent on the size of the nanowires. By measuring the electrical conduction of doped silicon nanowires as a function of nanowire radius, temperature and dielectric surrounding, we show that the donor ionization energy increases with decreasing nanowire radius, and that it profoundly modifies the attainable free carrier density at values of the radius much larger than those at which quantum and dopant surface segregation effects set in. At a nanowire radius of 15 nm the carrier density is already 50% lower than in bulk silicon due to the dielectric mismatch between the conducting channel and its surroundings.

  7. Donor research in australia: challenges and promise.

    PubMed

    Masser, Barbara; Smith, Geoff; Williams, Lisa A

    2014-07-01

    Donors are the key to the core business of Blood Collection Agencies (BCAs). However, historically, they have not been a focus of research undertaken by these organizations. This model is now changing, with significant donor research groups established in a number of countries, including Australia. Donor research in the Australian Red Cross Blood Service (Blood Service) is concentrated in the Donor and Community Research (DCR) team. Cognizant of the complex and ever-changing landscape with regard to optimal donor management, the DCR team collaborates with academics located at universities around Australia to coordinate a broad program of research that addresses both short- and-long term challenges to the blood supply. This type of collaboration is not, however, without challenges. Two major collaborative programs of the Blood Service's research, focusing on i) the recruitment and retention of plasmapheresis donors and ii) the role of the emotion pride in donor motivation and return, are showcased to elucidate how the challenges of conducting collaborative BCA research can be met. In so doing, these and the other research programs described herein demonstrate how the Blood Service supports and contributes to research that not only revises operational procedures but also contributes to advances in basic science. PMID:25254025

  8. Donor Research in Australia: Challenges and Promise

    PubMed Central

    Masser, Barbara; Smith, Geoff; Williams, Lisa A.

    2014-01-01

    Summary Donors are the key to the core business of Blood Collection Agencies (BCAs). However, historically, they have not been a focus of research undertaken by these organizations. This model is now changing, with significant donor research groups established in a number of countries, including Australia. Donor research in the Australian Red Cross Blood Service (Blood Service) is concentrated in the Donor and Community Research (DCR) team. Cognizant of the complex and ever-changing landscape with regard to optimal donor management, the DCR team collaborates with academics located at universities around Australia to coordinate a broad program of research that addresses both short- and-long term challenges to the blood supply. This type of collaboration is not, however, without challenges. Two major collaborative programs of the Blood Service's research, focusing on i) the recruitment and retention of plasmapheresis donors and ii) the role of the emotion pride in donor motivation and return, are showcased to elucidate how the challenges of conducting collaborative BCA research can be met. In so doing, these and the other research programs described herein demonstrate how the Blood Service supports and contributes to research that not only revises operational procedures but also contributes to advances in basic science. PMID:25254025

  9. Sensitive, Fast, and Specific Immunoassays for Methyltestosterone Detection

    PubMed Central

    Kong, Na; Song, Shanshan; Peng, Juan; Liu, Liqiang; Kuang, Hua; Xu, Chuanlai

    2015-01-01

    An indirect competitive enzyme-linked immunosorbent assay (icELISA) and an immunochromatographic strip assay using a highly specific monoclonal antibody, were developed to detect methyltestosterone (MT) residues in animal feed. The optimized icELISA had a half-inhibition concentration value of 0.26 ng/mL and a limit of detection value of 0.045 ng/mL. There was no cross-reactivity with eight analogues, revealing high specificity for MT. Based on icELISA results, the recovery rate of MT in animal feed was 82.4%–100.6%. The results were in accordance with those obtained by gas chromatography-mass spectrometry. The developed immunochromatographic strip assay, as the first report for MT detection, had a visual cut-off value of 1 ng/mL in PBS, 2.5 ng/g in fish feed, and 2.5 ng/g in pig feed. Therefore, these immunoassays are useful and fast tools for MT residue detection in animal feed. PMID:25938198

  10. Lead analysis by anti-chelate fluorescence polarization immunoassay.

    PubMed

    Johnson, David K; Combs, Sherry M; Parsen, John D; Jolley, Michael E

    2002-03-01

    Lead concentrations were determined by a fluorescence polarization immunoassay (FPIA) method that uses polyclonal antibodies raised against the lead(II) chelate of ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA). The technique is based on competition for a fixed concentration of antibody binding sites between Pb-EDTA, formed by treating the sample with excess EDTA, and a fixed concentration of a fluorescent analogue of the Pb-EDTA complex. The objective was to correlate results obtained by FPIA with those produced by conventional atomic spectroscopy analysis of soils, solid waste leachates (produced by the Toxicity Characteristic Leachate Procedure; TCLP), airborne dust, and drinking water. Linear regression analysis of FPIA results for 138 soil samples containing 0-3094 ppm Pb(II) by flame atomic absorption spectroscopy and 40 TCLP extracts containing 0-668 ppm Pb(II) by inductively coupled plasma atomic emission spectroscopy produced correlation coefficients (r2) of 0.96 and 0.93, respectively. Pilot studies of mineral acid extracts of airborne dust trapped on fiberglass filters and of two sources of drinking water demonstrated the feasibility of also measuring lead in these matrixes by FPIA. The limit of detection under conditions that minimized sample dilution was approximately 1 ppb, and cross reactivity with 15 nontarget metals was below 0.5% in all cases. The methods are simple to perform and are amenable to field testing and mobile laboratory use, allowing timely and cost-effective characterization of suspected sources of lead contamination. PMID:11917989

  11. Preparation of horseradish peroxidase hydrazide and its use in immunoassay.

    PubMed

    Shrivastav, Tulsidas G

    2003-01-01

    Preparation of horseradish peroxidase (HRP) hydrazide that is HRP linked to adipic acid dihydrazide (HRP-ADH) and its use in enzyme immunoassay (EIA) is described. In this new strategy, horseradish peroxidase was conjugated to adipic acid dihydrazide using a carbodiimide coupling method. The resulting HRP-ADH was then coupled to cortisol-21-hemisuccinate (Cortisol-21-HS) to prepare enzyme conjugate. The prepared cortisol-21-HS coupled ADH-HRP (Cortisol-21-HS-ADH-HRP) enzyme conjugate was used for the development of an enzyme linked immunosorbent assay (ELISA) for direct estimation of cortisol. To the cortisol antibody coated microtiter wells, standard or serum samples (50 microL), along with cortisol-21-HS-ADH-HRP enzyme conjugate (100 microL) were incubated for 1 h at 37 degrees C. Bound enzyme activity was measured by using tetramethyl benzidine/hydrogen peroxide (TMB/H2O2) as substrate. The sensitivity of the assay was 0.05 microg/dL and the analytical recovery ranged from 92.9 to 101.7%. PMID:12953974

  12. Rapid dioxin screening of milk and water by enzyme immunoassay

    SciTech Connect

    Harrison, R.O.; Carlson, R.E.; Shirkhan, H.

    1995-12-01

    A simple and easy to use enzyme immunoassay (EIA) system has been developed for rapid screening of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378D). This EIA has been adapted to analysis of water and milk using an automated system for extraction of liquid samples. Water analysis can be performed directly following extraction and solvent exchange with no extract clean-up. The same automated system is used for milk extraction and the extract is then cleaned chromatographically using the automated FMS Dioxin-Prep{trademark} System. Sensitivity for 2378D in the EIA is approximately 100 pg per analysis. Thus sensitivity to 10 ppt 2378D (whole weight basis) in milk is possible using only 50 ml or less of sample and sensitivity to 0.1 ppt 2378D in water is possible using 1-2 liters of sample. Total time for sample preparation and analysis is about 3 hours for water and 4.5 hours for milk.

  13. Surface plasmon resonance-based immunoassay for procalcitonin.

    PubMed

    Vashist, Sandeep Kumar; Schneider, E Marion; Barth, Eberhard; Luong, John H T

    2016-09-28

    A surface plasmon resonance (SPR) biosensor has been developed for rapid immunoassay of procalcitonin (PCT) with high detection sensitivity and reproducibility. The 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC)-activated protein A (PrA), diluted in 1% (v/v) 3-aminopropyltriethoxysilane (APTES) was dispensed on a KOH-treated Au-coated SPR chip, resulting in the covalent binding of PrA in 30 min. This "single-step" PrA immobilization strategy led to the oriented binding of the anti-PCT antibody (Ab) on a PrA-functionalized gold (Au) chip. The leach-proof immobilization procedure is five-fold faster than conventional counterparts, enabling high detection specificity and reproducibility. The IA detects 4-324 ng mL(-1) of PCT with a limit of detection (LOD) and a limit of quantification (LOQ) of 4.2 ng mL(-1) and 9.2 ng mL(-1), respectively. It was capable of detecting PCT in real sample matrices and patient samples with high precision. The Ab-bound SPR chips were stable for more than five weeks. PMID:27619095

  14. A Portable Analyzer for Pouch-Actuated, Immunoassay Cassettes

    PubMed Central

    Qiu, Xianbo; Liu, Changchun; Mauk, Michael G.; Hart, Robert W.; Chen, Dafeng; Qiu, Jing; Kientz, Terry; Fiene, Jonathan; Bau, Haim H.

    2011-01-01

    A portable, small footprint, light, general purpose analyzer (processor) to control the flow in immunoassay cassettes and to facilitate the detection of test results is described. The durable analyzer accepts disposable cassettes that contain pouches and reaction chambers for various unit operations such as hydration of dry reagents, stirring, and incubation. The analyzer includes individually controlled, linear actuators to compress the pouches in the cassette, which facilitates the pumping and mixing of sample and reagents, and to close diaphragm-based valves for flow control. The same types of actuators are used to compress pouches and actuate valves. The analyzer also houses a compact OEM scanner/reader to excite fluorescence and detect emission from labels. The analyzer is hydraulically isolated from the cassette, reducing the possibility of cross-contamination. The analyzer facilitates programmable, automated execution of a sequence of operations such as pumping and valving in a timely fashion, reducing the level of expertise required from the operator and the possibility for errors. The analyzer’s design is modular and expandable to accommodate cassettes of various complexities and additional functionalities. In this paper, the utility of the analyzer has been demonstrated with the execution of a simple, consecutive, lateral flow assay of a model biological system and the test results were detected with up converting phosphor labels that are excited at infrared frequencies and emit in the visible spectrum. PMID:22125359

  15. Designing novel nano-immunoassays: antibody orientation versus sensitivity

    NASA Astrophysics Data System (ADS)

    Puertas, S.; Moros, M.; Fernández-Pacheco, R.; Ibarra, M. R.; Grazú, V.; de la Fuente, J. M.

    2010-12-01

    There is a growing interest in the use of magnetic nanoparticles (MNPs) for their application in quantitative and highly sensitive biosensors. Their use as labels of biological recognition events and their detection by means of some magnetic method constitute a very promising strategy for quantitative high-sensitive lateral-flow assays. In this paper, we report the importance of nanoparticle functionalization for the improvement of sensitivity for a lateral-flow immunoassay. More precisely, we have found that immobilization of IgG anti-hCG through its polysaccharide moieties on MNPs allows more successful recognition of the hCG hormone. Although we have used the detection of hCG as a model in this work, the strategy of binding antibodies to MNPs through its sugar chains reported here is applicable to other antibodies. It has huge potential as it will be very useful for the development of quantitative and high-sensitive lateral-flow assays for its use on human and veterinary, medicine, food and beverage manufacturing, pharmaceutical, medical biologics and personal care product production, environmental remediation, etc.

  16. Integrated microfluidic immunoassay for the rapid determination of clenbuterol.

    PubMed

    Kong, Jing; Jiang, Lei; Su, Xiaoou; Qin, Jianhua; Du, Yuguang; Lin, Bingcheng

    2009-06-01

    An integrated microfluidic immunoassay system was established for high throughput analysis of clenbuterol. This system consisted of an integrated microchip and a linear confocal laser induced fluorescence (LIF) scanner. The microchip was composed of three layers: a fluidic channel layer, a PDMS membrane layer and a pneumatic control layer. The multi-layer chip was integrated with 36 pneumatic micro-valves and multiple micro-pumps to realize the flexible reagent delivery, facilitating the automatic assays with less consumption of samples and reduced analysis time. The homemade LIF scanner was able to simultaneously detect multi-channels and provide the potential capability of high throughput assays. The performance of the system was demonstrated by the determination of clenbuterol, one of the most widely used beta-agonists. Under the optimal conditions, the linear range and the limit of detection of clenbuterol were 0 approximately 5.0 ng mL(-1) and 0.088 ng mL(-1), respectively. The recovery rates determined with pig urine samples of 1.0 ng mL(-1) and 2.0 ng mL(-1) were 98.74% and 102.51% (n = 3), respectively. The total detection time was less than 30 min. The system had the potential application for rapid detection of multiple beta-agonists in clinical, pharmaceutical and chemical analyses. PMID:19458860

  17. Backscattering particle immunoassays in wire-guide droplet manipulations.

    PubMed

    Yoon, Jeong-Yeol; You, David J

    2008-01-01

    A simpler way for manipulating droplets on a flat surface was demonstrated, eliminating the complications in the existing methods of open-surface digital microfluidics. Programmed and motorized movements of 10 muL droplets were demonstrated using stepper motors and microcontrollers, including merging, complicated movement along the programmed path, and rapid mixing. Latex immunoagglutination assays for mouse immunoglobulin G, bovine viral diarrhea virus and Escherichia coli were demonstrated by merging two droplets on a superhydrophobic surface (contact angle = 155 +/- 2 degrees ) and using subsequent back light scattering detection, with detection limits of 50 pg mL-1, 2.5 TCID50 mL-1 and 85 CFU mL-1, respectively, all significantly lower than the other immunoassay demonstrations in conventional microfluidics (~1 ng mL-1 for proteins, ~100 TCID50 mL-1 for viruses and ~100 CFU mL-1 for bacteria). Advantages of this system over conventional microfluidics or microwell plate assays include: (1) minimized biofouling and repeated use (>100 times) of a platform; (2) possibility of nanoliter droplet manipulation; (3) reprogrammability with a computer or a game pad interface. PMID:19014703

  18. Sensitive giant magnetoresistive-based immunoassay for multiplex mycotoxin detection.

    PubMed

    Mak, Andy C; Osterfeld, Sebastian J; Yu, Heng; Wang, Shan X; Davis, Ronald W; Jejelowo, Olufisayo A; Pourmand, Nader

    2010-03-15

    Rapid and multiplexed measurement is vital in the detection of food-borne pathogens. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment (e.g. fluorescent labels) and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for mycotoxins that functions on a sub-picomolar concentration level. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the system presented here, each spin-valve sensor has an active area of 90 microm x 90 microm, arranged in an 8 x 8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response is recorded in real time upon the addition of streptavidin-linked MNTs on the chip. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B(1), zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved. PMID:20047828

  19. A Microsystem for Magnetic Immunoassay Based on Planar Microcoil Array.

    PubMed

    Zheng, Yushan; Shang, Nan; Haddad, Pierre S; Sawan, Mohamad

    2016-04-01

    This work focuses on the circuit and system implementation of a microsystem platform for magnetic immunoassay, which is a novel type of diagnostic method using magnetic beads as labels. Three main challenges facing this work-design of a high performance sensor, packaging technique and design of integrated circuits are discussed. Planar microcoil array are exploited as sensor of magnetic beads, whereas ultra thin bottom microplate in traditional ELISA is used for the assay. Main circuits blocks include bidirectional current supply circuit, magnetic field sensing circuit and on-chip temperature sensor. Experiments using mouse IgG with different densities were performed on the proposed platform, results show that a minimum density of 100 pg/mL can be detected, which is a comparable sensitivity to conventional optical ELISA, and a quantitative relationship can be acquired in the range from 1 ng/ml to 1 ug/ml, thus this platform is suitable for quantitative analysis in practical health and environment application and has potential for medical diagnostics, food pathogen detection or water analysis. PMID:26173219

  20. Development of sub-micron patterned carbon electrodes for immunoassays.

    PubMed

    Dontha, N; Nowall, W B; Kuhr, W G

    1999-02-01

    Sub-micron sized domains of a carbon surface are derivatized with antibodies using biotin/avidin technology. These sites are spatially-segregated from, and directly adjacent to, electron transfer sites on the same electrode surface. The distance between these electron transfer sites and enzyme-loaded domains are kept to a minimum (e.g. less than a micron) to maintain the high sensitivity required for the measurement of enzyme-linked cofactors in an enzyme-linked immunoassay (ELISA). This is accomplished through the use of photolithographic attachment of photobiotin using an interference pattern from a UV laser generated at the electrode surface. This allows the construction of microscopic arrays of active ELISA sites on a carbon substrate while leaving other sites underivatized to facilitate electron transfer reactions of redox mediators; thus maximizing sensitivity and detection of the enzyme mediator. The carbon electrode surface is characterized with respect to its chemical structure and electron transfer properties following each step of the antibody immobilization process. The characterization of specific modifications of micron regions of the carbon surface requires analytical methodology that has both high spatial resolution and sensitivity. We have used fluorescence microscopy with a cooled CCD imaging system to visualize the spatial distribution of enzyme immobilization sites (indicated by fluorescence from Texas-Red labeled antibody) across the carbon surface. The viability of the enzyme attached to the surface in this manner was demonstrated by imaging the distribution of an insoluble, fluorescent product. PMID:10698570

  1. The microassay on a card: A rugged, portable immunoassay

    NASA Technical Reports Server (NTRS)

    Kidwell, David

    1991-01-01

    The Microassay on a Card (MAC) is a portable, hand-held, non-instrumental immunoassay that can test for the presence of a wide variety of substances in the environment. The MAC is a simple device to use. A drop of test solution is placed on one side of the card and within five minutes a color is developed on the other side in proportion to the amount of substance in the test solution, with sensitivity approaching 10 ng/ml. The MAC is self-contained and self-timed; no reagents or timing is necessary. The MAC may be configured with multiple wells to provide simultaneous testing for multiple species. As envisioned, the MAC will be employed first as an on-site screen for drugs of abuse in urine or saliva. If the MAC can be used as a screen of saliva for drugs of abuse, it could be applied to driving while intoxicated, use of drugs on the job, or testing of the identity of seized materials. With appropriate modifications, the MAC also could be used to test for environmental toxins or pollutants.

  2. Optical immunoassay systems based upon evanescent wave interactions

    NASA Astrophysics Data System (ADS)

    Christensen, Douglas A.; Herron, James N.

    1996-04-01

    Immunoassays based upon evanescent wave interactions are finding increased biosensing application. In these devices, the evanescent tail associated with total internal reflection of an incident beam at the substrate/solution interface provides sensitivity for surface-bound protein over bulk molecules, allowing homogeneous assays and real-time measurement of binding dynamics. Among such systems are surface plasmon resonance sensors and a resonant mirror device. Several research groups are also developing fluorescent fiberoptic or planar waveguide sensors for biomedical applications. We describe a second-generation planar waveguide fluoroimmunoassay system being developed in our laboratory which uses a molded polystyrene sensor. The 633-nm beam from a laser diode is focused into the 500 micrometer- thick planar waveguide by an integral lens. Antibodies to the desired analyte (hCG) are immobilized on the waveguide surface and fluorescence from bound analyte/tracer antibodies in a sandwich format is imaged onto the detector. The geometry of the waveguide allows several zones to be detected, providing the capability for on-sensor calibration. This sensor has shown picomolar sensitivity for the detection of hCG.

  3. Amplified flow-cytometric separation-free fluorescence immunoassays

    SciTech Connect

    Saunders, G.C.; Jett, J.H.; Martin, J.C.

    1985-12-01

    An equilibrium-type competitive-binding fluorescence immunoassay with high sensitivity and excellent precision is described that obviates separation of free from bound label. In the assay relatively large (10 microns diameter) antibody-coated non-fluorescent particles and very small (0.10 micron diameter) antigen-coated fluorescent latex particles are used. Soluble nonlabeled antigen competes with antigen on the microspheres for antibody binding sites on the larger spheres. After equilibrium is attained, the fluorescence distribution of 5000 of the large spheres is measured in a flow cytometer. The mean values for the fluorescence distribution obtained from samples containing known concentrations of soluble antigen are used to construct a standard displacement curve. In a prototype assay for the antigen horseradish peroxidase, a sensitivity of 10(-12) mol/L has been achieved. Undiluted serum can be assayed without loss of sensitivity. Preliminary experiments also indicate that double-antibody sandwich-type assays of very high sensitivity (10(-14) mol/L) are also possible when this dual-sphere concept is exploited.

  4. Cavity-Enhanced Immunoassay Measurements in Microtiter Plates Using BBCEAS.

    PubMed

    Bajuszova, Zuzana; Ali, Zulfiqur; Scott, Simon; Seetohul, L Nitin; Islam, Meez

    2016-05-17

    We report on the first detailed use of broadband cavity enhanced absorption spectroscopy (BBCEAS) as a detection system for immunoassay. A vertical R ≥ 0.99 optical cavity was integrated with a motorized XY stage, which functioned as a receptacle for 96-well microtiter plates. The custom-built cavity enhanced microplate reader was used to make measurements on a commercially available osteocalcin sandwich ELISA kit. A 30-fold increase in path length was obtained with a minimum detectable change in the absorption coefficient, αmin(t), of 5.3 × 10(-5) cm(-1) Hz(-1/2). This corresponded to a 39-fold increase in the sensitivity of measurement when directly compared to measurements in a conventional microplate reader. Separate measurements of a standard STREP-HRP colorimetric reaction in microtiter plates of differing optical quality produced an increase in sensitivity of up to 115-fold compared to a conventional microplate reader. The sensitivity of the developed setup compared favorably with previous liquid-phase cavity enhanced studies and approaches the sensitivity of typical fluorometric ELISAs. It could benefit any biochemical test which uses single pass absorption as a detection method, through either the label free detection of biologically important molecules at lower concentrations or the reduction in the amount of expensive biochemicals needed for a particular test, leading to cheaper tests. PMID:27089516

  5. Bioluminescent enzyme immunoassay for the detection of norovirus capsid antigen.

    PubMed

    Sakamaki, Nozomi; Ohiro, Yoshiyuki; Ito, Mitsuki; Makinodan, Mitsuru; Ohta, Tsubasa; Suzuki, Wataru; Takayasu, Susumu; Tsuge, Harufumi

    2012-12-01

    An ultrasensitive and fully automated bioluminescent enzyme immunoassay (BLEIA) was developed for the detection of norovirus (NV) capsid antigen. In the evaluation tests with recombinant virus-like particles, the BLEIA demonstrated broad reactivity against several NV genotypes (genotypes 1, 3, 4, 7, 8, and 12 in genogroup I [GI] and genotypes 1, 2, 3, 4, 5, 6, 12, and 13 in GII), a wide dose-response range from 0.25 pg/ml to 10,000 pg/ml, and good reproducibility with low coefficients of variation (CVs) (within-run CVs of <2.8%, between-day CVs of <3.7%). In the evaluation tests with NV-positive fecal samples, a good correlation (y = 0.66x - 3.21, r = 0.84) between the BLEIA and real-time quantitative reverse transcription-PCR was obtained. Furthermore, in the dilution test with NV specimens, the analytical sensitivity of NV was estimated to be 10(5) to 10(6) copies/g of fecal sample, indicating that the analytical sensitivity of the BLEIA is comparable to that of commercially available molecular methods. All assay steps are fully automated, the turnaround time is 46 min, and the throughput of the assay is 120 tests/h. These results indicate that the BLEIA is potentially useful for the rapid diagnosis of NV in epidemic and sporadic gastroenteritis. PMID:23081816

  6. Ultrasensitive photoelectrochemical immunoassay through tag induced exciton trapping.

    PubMed

    Wen, Guangming; Ju, Huangxian

    2015-03-01

    The development of photoelectrochemical (PEC) sensors with novel principles is of significance in realizing sensitive and low-cost detection. This work uses CuO NPs labeled antibody to construct a simple and sensitive sandwich-type immunobiosensor for the detection of protein. The detection signal is produced by dissolving the CuO NPs to release copper ions, which are then added on a quantum dots (QDs) modified F-doped tin oxide to quench the photocurrent of QDs via copper ion-induced formation of exciton trapping. The formed exciton trapping blocks the escape of photoelectron and thus leads to a "signal off" PEC method for sensitive immunoassay. The proposed method shows a detectable range from 0.05 to 500 ng/mL for α-fetoprotein (AFP) with a detection limit (LOD) of 0.038 ng/mL. This work further extends the application of exciton trapping-based PEC biosensing strategy in bioanalysis. The sensitive analytical performance of the designed route implies a promising potential of the PEC sensing in clinical diagnosis. PMID:25618699

  7. Enzyme immunoassay for measuring 25-hydroxyvitamin D3 in serum.

    PubMed

    Lind, C; Chen, J; Byrjalsen, I

    1997-06-01

    We developed a rapid, competitive enzyme immunoassay (EIA) for measuring 25-hydroxyvitamin D3 [25(OH)D3] in serum. The EIA was based upon 25(OH)D3-3-hemisuccinate covalently coupled to secondary amino groups grafted onto the polystyrene surface of microtiter wells. Optimal coupling conditions were established, and we found that inclusion of 40 mumol/L chloramine T, an agent not previously described for use in coupling to these plates, resulted in both more reproducible coupling as well as more than a twofold increase in the coupling efficiency. Before EIA, 25(OH)D3 was extracted from the serum samples by acetonitrile, and the redissolved extract was incubated with polyclonal rabbit antibody raised against 1,25-dihydroxyvitamin D3-3-hemisuccinate conjugated to bovine serum albumin. Peroxidase-labeled antibody raised in goat against rabbit immunoglobulins was used for detection. The detection limit of the EIA was 4.4 micrograms/L; recovery 102%; on-plate CV 11%; within-run CV including extraction 12%, and between-run CV 15%. There was no clinically important cross-reactivity with other vitamin D metabolites, and results obtained by the EIA were compared with results obtained by a previously described RIA. PMID:9191544

  8. System and method for a parallel immunoassay system

    DOEpatents

    Stevens, Fred J.

    2002-01-01

    A method and system for detecting a target antigen using massively parallel immunoassay technology. In this system, high affinity antibodies of the antigen are covalently linked to small beads or particles. The beads are exposed to a solution containing DNA-oligomer-mimics of the antigen. The mimics which are reactive with the covalently attached antibody or antibodies will bind to the appropriate antibody molecule on the bead. The particles or beads are then washed to remove any unbound DNA-oligomer-mimics and are then immobilized or trapped. The bead-antibody complexes are then exposed to a test solution which may contain the targeted antigens. If the antigen is present it will replace the mimic since it has a greater affinity for the respective antibody. The particles are then removed from the solution leaving a residual solution. This residual solution is applied a DNA chip containing many samples of complimentary DNA. If the DNA tag from a mimic binds with its complimentary DNA, it indicates the presence of the target antigen. A flourescent tag can be used to more easily identify the bound DNA tag.

  9. Living donor liver transplantation in Egypt

    PubMed Central

    Marwan, Ibrahim

    2016-01-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15−59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt. PMID:27115003

  10. Living donor liver transplantation in Egypt.

    PubMed

    Amer, Khaled E; Marwan, Ibrahim

    2016-04-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15-59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt. PMID:27115003

  11. Complications in 100 living-liver donors.

    PubMed Central

    Grewal, H P; Thistlewaite, J R; Loss, G E; Fisher, J S; Cronin, D C; Siegel, C T; Newell, K A; Bruce, D S; Woodle, E S; Brady, L; Kelly, S; Boone, P; Oswald, K; Millis, J M

    1998-01-01

    OBJECTIVE: A review of 100 living-liver donors was performed to evaluate the perisurgical complications of the procedure and thus to help quantify the risks to the donor. SUMMARY BACKGROUND DATA: Despite the advantages of living-donor liver transplantation (LDLT), the procedure has received criticism for the risk it imposes on healthy persons. A paucity of data exists regarding the complications and relative safety of the procedure. METHODS: One hundred LDLTs performed between November 1989 and November 1996 were reviewed. Donor data were obtained by chart review, anesthesia records, and the computerized hospital data base. Patient variables were compared by Fisher's exact test and the Student's t test. RESULTS: There were 57 women and 43 men with a median age of 29. Donors were divided into two groups: group A (first 50 donors), and group B (last 50 donors). There were 91 left lateral segments and 9 left lobes. There were no deaths. Fourteen major complications occurred in 13 patients; 9 occurred in group A and 5 in group B. Biliary complications consisted of five bile duct injuries (group A = 4, group B = 1) and two cut edge bile leaks. Complications were more common in left lobe resections (55%) than in left lateral segment grafts (10%). Minor complications occurred in 20% of patients. A significant reduction in overall complications (major and minor) was observed between the groups (group A, n = 24 [45%] vs. group B, n = 10 [20%]). In addition, surgical time and hospital stay were both significantly reduced. CONCLUSIONS: Although the procedure is safe, many LDLT donors have a perisurgical complication. Surgical experience and technical modifications have resulted in a significant reduction in these complications, however. To minimize the risks for these healthy donors, LDLT should be performed at institutions with extensive experience. PMID:9712567

  12. Reassessing Medical Risk in Living Kidney Donors

    PubMed Central

    Kumar, Vineeta; Matas, Arthur J.

    2015-01-01

    The short- and long-term effects of unilateral nephrectomy on living donors have been important considerations for 60 years. Short-term risk is well established (0.03% mortality and <1% risk of major morbidity), but characterization of long-term risk is evolving. Relative to the general population, risk of mortality, ESRD, hypertension, proteinuria, and cardiovascular disease is comparable or lower. However, new studies comparing previous donors with equally healthy controls indicate increased risk of metabolic derangements (particularly involving calcium homeostasis), renal failure, and possibly, mortality. We discuss how these results should be interpreted and their influence on the practice of living donor kidney transplantation. PMID:25255922

  13. Granulocyte kinetics in donors undergoing filtration leukapheresis.

    PubMed

    Rubins, J M; MacPherson, J L; Nusbacher, J; Wiltbank, T

    1976-01-01

    Normal blood donors undergoing filtration leukapheresis (FL) have a profound transient neutropenia early in the procedure which is followed by a "rebound" neutrophilia. This phenomenon occurs in unstimulated donors as well as in donors pretreated with either prednisone or dexamethasone. The mechanism for development of the neutropenia was investigated in volunteers throug a nylon filter at 37 C, a significant but transient neutropenia was observed. Plasma rendered cell and stroma-free achieved the same result indicating that plasma alone, when exposed to nylon fibers, is capable of producing neutropenia. PMID:1251458

  14. Interventional radiology in living donor liver transplant

    PubMed Central

    Cheng, Yu-Fan; Ou, Hsin-You; Yu, Chun-Yen; Tsang, Leo Leung-Chit; Huang, Tung-Liang; Chen, Tai-Yi; Hsu, Hsien-Wen; Concerjero, Allan M; Wang, Chih-Chi; Wang, Shih-Ho; Lin, Tsan-Shiun; Liu, Yueh-Wei; Yong, Chee-Chien; Lin, Yu-Hung; Lin, Chih-Che; Chiu, King-Wah; Jawan, Bruno; Eng, Hock-Liew; Chen, Chao-Long

    2014-01-01

    The shortage of deceased donor liver grafts led to the use of living donor liver transplant (LDLT). Patients who undergo LDLT have a higher risk of complications than those who undergo deceased donor liver transplantation (LT). Interventional radiology has acquired a key role in every LT program by treating the majority of vascular and non-vascular post-transplant complications, improving graft and patient survival and avoiding, in the majority of cases, surgical revision and/or re-transplant. The aim of this paper is to review indications, diagnostic modalities, technical considerations, achievements and potential complications of interventional radiology procedures after LDLT. PMID:24876742

  15. Feelings of living donors about adult-to-adult living donor liver transplantation.

    PubMed

    Kusakabe, Tomoko; Irie, Shinji; Ito, Naomi; Kazuma, Keiko

    2008-01-01

    This study investigated the feelings of living donors about adult-to-adult liver transplantation. We interviewed 18 donors about their feelings before and after transplantation using semistructured interviews and then conducted a content analysis of their responses. Before transplantation, many donors reported that they wanted recipients to live for the donor or his or her family, and there was no one else to donate. Many donors were not anxious, did not feel coerced, and did not consider donation dangerous. Some reported being excited at facing a new experience. Some said they would not mind whatever happens. Others were anxious or unsure about the operation. Diagnostic testing and preoperative blood banking were painful. Donors experienced increasing stress just before the operation. After transplantation, some donors verbalized feeling more grateful to others and that they gained maturity. Throughout the process, donors were concerned about their recipients. Our results suggest that donors might act for themselves or their family. It is important to recognize the varied responses of donors' feelings toward liver transplant recipients. PMID:18708830

  16. Donor Retention in Online Crowdfunding Communities: A Case Study of DonorsChoose.org

    PubMed Central

    Althoff, Tim; Leskovec, Jure

    2016-01-01

    Online crowdfunding platforms like DonorsChoose.org and Kick-starter allow specific projects to get funded by targeted contributions from a large number of people. Critical for the success of crowdfunding communities is recruitment and continued engagement of donors. With donor attrition rates above 70%, a significant challenge for online crowdfunding platforms as well as traditional offline non-profit organizations is the problem of donor retention. We present a large-scale study of millions of donors and donations on DonorsChoose.org, a crowdfunding platform for education projects. Studying an online crowdfunding platform allows for an unprecedented detailed view of how people direct their donations. We explore various factors impacting donor retention which allows us to identify different groups of donors and quantify their propensity to return for subsequent donations. We find that donors are more likely to return if they had a positive interaction with the receiver of the donation. We also show that this includes appropriate and timely recognition of their support as well as detailed communication of their impact. Finally, we discuss how our findings could inform steps to improve donor retention in crowdfunding communities and non-profit organizations. PMID:27077139

  17. Non-organ donors' attitudes toward incentives.

    PubMed

    Tumin, Makmor; Noh, Abdillah; Chong, Chin-Sieng; Lim, Soo-Kun; Abdullah, Nawi; Ng, Kok-Peng

    2013-01-01

    Malaysians indicating that they did not intend to become organ donors upon their death were surveyed regarding interest in non-fungible financial incentives to be granted to surviving family members. Among the 730 (56% of the total sample of 1311) indicating unwillingness to be donors, 29.6% (216/730) subsequently indicated that they would be willing donors if the government introduced policies that, upon their death, "rewarded your (their) family with incentives for your (their) deeds." Among the 69% (504/730) who insisted that they would not become organ donor even with incentive, nearly 80% (404/501) of them were able to identify relevant incentives they thought should be provided by the state to those who make organ donations upon death. The majority of both groups preferred the state provide medical benefits to a surviving family member, suggesting this may be an attractive policy option for the state to raise the deceased organ donation pool. PMID:23600843

  18. Solicited kidney donors: Are they coerced?

    PubMed

    Serur, David; Bretzlaff, Gretchen; Christos, Paul; Desrosiers, Farrah; Charlton, Marian

    2015-12-01

    Most non-directed donors (NDDs) decide to donate on their own and contact the transplant centre directly. Some NDDs decide to donate in response to community solicitation such as newspaper ads or donor drives. We wished to explore whether subtle coercion might be occurring in such NDDs who are part of a larger community. One successful organization in a community in Brooklyn, NY, provides about 50 NDDs per year for recipients within that community. The donors answer ads in local papers and attend donor drives. Herein, we evaluated the physical and emotional outcomes of community-solicited NDDs in comparison to traditional NDDs who come from varied communities and are not responding to a specific call for donation. An assessment of coercion was used as well. PMID:26511772

  19. Hydrogen enhancement of silicon thermal donor formation

    NASA Astrophysics Data System (ADS)

    Lamp, C. D.; James, D. J., II

    1993-04-01

    Oxygen-related thermal donor formation in Czochralski silicon is characterized by the capacitance-voltage and deep level transient spectroscopy techniques as a function of 450 °C anneal time following hydrogenation. Increases in the formation rate and number of thermal donor (TD) defects found after hydrogenation are reported. This study finds an increase in TD+/++ concentration in the near-surface region at short anneal times, but at longer times an elevated concentration was not observed. No acceleration through the sequence of thermal donor defects was detected. This fails to support the model of hydrogen lowering the barrier to oxygen diffusion and accelerating the TDn→TDn+1 transitions. This study does, however, support a model in which the hydrogen increases the available thermal donor core sites.

  20. Living donor liver transplantation in the USA

    PubMed Central

    Testa, Giuliano

    2016-01-01

    Living donor liver transplant (LDLT) accounts for a small volume of the transplants in the USA. Due to the current liver allocation system based on the model for end-stage liver disease (MELD), LDLT has a unique role in providing life-saving transplantation for patients with low MELD scores and significant complications from portal hypertension, as well as select patients with hepatocellular carcinoma (HCC). Donor safety is paramount and has been a topic of much discussion in the transplant community as well as the general media. The donor risk appears to be low overall, with a favorable long-term quality of life. The latest trend has been a gradual shift from right-lobe grafts to left-lobe grafts to reduce donor risk, provided that the left lobe can provide adequate liver volume for the recipient. PMID:27115007

  1. Human T-Lymphotropic Virus Type 1 and 2 Seroprevalence among first-time blood donors in Chile, 2011-2013.

    PubMed

    San Martín, Héctor; Balanda, Monserrat; Vergara, Nicolás; Valenzuela, María Antonieta; Cartier, Luis; Ayala, Salvador; Ramírez, Eugenio

    2016-06-01

    Infection with human T-lymphotropic virus type 1/2 (HTLV-1/2) is a major health problem. HTLV-1/2 infection is endemic in Chile but representative donor prevalence data are lacking. Data on all blood donors in a large network of Chilean blood centers were examined during 2011-2013. Screening of HTLV-1/2 antibodies were measured by enzyme immunoassay (EIA) at all blood banks. Blood samples with anticoagulants from initially reactive blood donors were analyzed by serological confirmation tests (immunofluorescence or recombinant immunoblot) at the HTLV National Reference Laboratory of the Public Health Institute of Chile. Additionally, detection of HTLV-1 and HTLV-2 provirus in peripheral blood mononuclear cells (PBMCs) was performed in all blood donors as confirmatory test. Prevalence rates were calculated. Among 694,016 donors, 706 were seropositive for HTLV-1 (prevalence, 1.02 cases per 1,000; 95% confidence interval [CI], 0.94-1.09), and 97 were seropositive for HTLV-2 (prevalence, 0.14 cases per 1,000; 95%CI, 0.11-0.17). Prevalence of HTLV-1 differed considerably by region, from 0.51 to 1.69 per 1,000. Prevalence of HTLV-2 was similar across the country (0.12-0.16). HTLV-1 prevalence was associated with female sex, older age, and residence in the north of Chile. HTVL-2 prevalence was associated with older age. The HTLV-1 prevalence among Chilean blood donors was relatively high and could be reduced by improving donor recruitment and selection in high prevalence areas. Blood center data may contribute to surveillance for HTLV-1 and HTLV-2 infections. PMID:26538335

  2. A Study of Seroprevalence and Rates of Asymptomatic Viremia of Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) among Chinese Blood Donors

    PubMed Central

    Zeng, Peibin; Ma, Lili; Gao, Zhan; Wang, Jingxing; Liu, Jing; Huang, Xianwei; Yang, Qizhi; Cao, Ruan; Wen, Xiuqiong; Zhu, Lili; Ma, Hongli; Yang, Zhendong; Lee, Tzong-Hae; Brambilla, Donald; Yuan, Michelle; Glynn, Simone; Ness, Paul; Kleinman, Steve; Busch, Michael; Shan, Hua

    2014-01-01

    Background SFTSV, an emerging tick-borne pathogen that can cause fatal severe fever with thrombocytopenia syndrome (SFTS), was first identified in China in 2009. Limited evidence suggests that SFTSV can be transmitted between humans via blood contact raising concerns over transfusion safety. A study of donor samples from three Chinese blood centers was conducted to investigate the seroprevalence and rate of SFTSV viremia among Chinese blood donors. Materials and Methods From April 16 to Oct 31, 2012, 17,208 plasma samples were collected from donors at Xinyang (located in an SFTSV endemic area), Mianyang and Luoyang blood centers. Assessment of anti-SFTSV total antibody was performed on all samples using Enzyme Linked Immunoassay (ELISA). Repeat-reactive samples were tested for SFTSV RNA using reverse transcription (RT) Real-time-PCR assay with Taqman probes. In addition, 9960 of the Xinyang samples were tested in pools of 4 by the same PCR method and each of samples in a reactive pool was tested individually. Results Donor seroreactivity rates were: Xinyang, 0.54% (80/14,752); Mianyang, 0.27% (3/1,130); and Luoyang, 0.28% (3/1,326). All seroreactive samples were negative on RT-PCR single-sample testing. Two RT-PCR reactive donor samples were identified, both with estimated viral load <20pfu/ml. The RNA prevalence rate for SFTSV among donors in Xinyang was 0.02%. Conclusion This was the first multi-region study of SFTSV sero- and viral-prevalence among Chinese blood donors. Viral prevalence was low and no seroreactive sample was viremic, suggesting limited impact of SFTSV on blood safety in China. PMID:25496479

  3. Cross-reactivity of steroid hormone immunoassays: clinical significance and two-dimensional molecular similarity prediction

    PubMed Central

    2014-01-01

    Background Immunoassays are widely used in clinical laboratories for measurement of plasma/serum concentrations of steroid hormones such as cortisol and testosterone. Immunoassays can be performed on a variety of standard clinical chemistry analyzers, thus allowing even small clinical laboratories to do analysis on-site. One limitation of steroid hormone immunoassays is interference caused by compounds with structural similarity to the target steroid of the assay. Interfering molecules include structurally related endogenous compounds and their metabolites as well as drugs such as anabolic steroids and synthetic glucocorticoids. Methods Cross-reactivity of a structurally diverse set of compounds were determined for the Roche Diagnostics Elecsys assays for cortisol, dehydroepiandrosterone (DHEA) sulfate, estradiol, progesterone, and testosterone. These data were compared and contrasted to package insert data and published cross-reactivity studies for other marketed steroid hormone immunoassays. Cross-reactivity was computationally predicted using the technique of two-dimensional molecular similarity. Results The Roche Elecsys Cortisol and Testosterone II assays showed a wider range of cross-reactivity than the DHEA sulfate, Estradiol II, and Progesterone II assays. 6-Methylprednisolone and prednisolone showed high cross-reactivity for the cortisol assay, with high likelihood of clinically significant effect for patients administered these drugs. In addition, 21-deoxycortisol likely produces clinically relevant cross-reactivity for cortisol in patients with 21-hydroxylase deficiency, while 11-deoxycortisol may produce clinically relevant cross-reactivity in 11β-hydroxylase deficiency or following metyrapone challenge. Several anabolic steroids may produce clinically significant false positives on the testosterone assay, although interpretation is limited by sparse pharmacokinetic data for some of these drugs. Norethindrone therapy may impact immunoassay measurement

  4. Utilization of Expanded Criteria Donors in Liver Transplantation

    PubMed Central

    Saidi, Reza F.

    2013-01-01

    Improvements in surgical techniques, immunosuppression, and post-transplantation patient care have led to the optimization of liver transplantation outcomes. However, the waiting list for liver transplantation is increasing at a greater pace. The large gap between the growing pool of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donors and identify new sources. This article will be focused on the current state of liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis) and from donation after cardiac death (DCD), as well as the use of partial grafts (split grafts and living-donor liver transplantation) and other suboptimal donors (donors with hypernatremia, infections, hypotension and inotropic support). Overall, broadened criteria for acceptable donor livers appear to lessen graft survival rates somewhat compared with rates for standard criteria organs. PMID:25013654

  5. Liver-specific deceased donor risk indices.

    PubMed

    Wang, Zifa; Hisatake, Garrett; Yang, Libin

    2014-02-01

    In order to assess the quality of the donor liver, procuring surgeons should accurately evaluate not only general donor risk indices, such as donor age, causes of brain death and cold ischemic time, but also consider the specific donor risk indices. In this review, we focus on liver-specific deceased donor risk indices, including liver steatosis, anti-hepatitis B core (HBc) positive or hepatitis C virus (HCV) positive donors, hypernatremia and anatomical variations. Liver steatosis is strongly associated with poor graft function after liver transplantation. Liver with more than 40-50% macrosteatosis should not be used. However, at present the quantity of fatty livers lack accepted standards. The computerized image analysis programs should be used to automate the determination of fat content in liver biopsy specimens. Liver grafts from anti-HBc positive donors can be safely used, preferentially in hepatitis B surface antigen (HBsAg) positive or anti-HBc/anti-HBs positive recipients. HCV positive allografts free from fibrosis or severe inflammation are a safe option for HCV positive recipients. The procurement team should consider liver biopsy to evaluate these HCV positive allografts. Donor serum sodium over 150 mm may predict a higher rate of graft primary non-functions. Recently, however, some investigators reported the sodium level likely has little clinical impact on post-transplant liver function. The incidence of hepatic artery variations has been reported to be approximately 30%. To avoid injuries, it is very important to know and identify these variations with precision at the time of organ procurement. PMID:24033790

  6. 25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays.

    PubMed

    Yu, Songlin; Cheng, Xinqi; Fang, Huiling; Zhang, Ruiping; Han, Jianhua; Qin, Xuzhen; Cheng, Qian; Su, Wei; Hou, Li'an; Xia, Liangyu; Qiu, Ling

    2015-01-01

    Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy. PMID:26420221

  7. 25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays

    PubMed Central

    Yu, Songlin; Cheng, Xinqi; Fang, Huiling; Zhang, Ruiping; Han, Jianhua; Qin, Xuzhen; Cheng, Qian; Su, Wei; Hou, Li’an; Xia, Liangyu; Qiu, Ling

    2015-01-01

    Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy. PMID:26420221

  8. Label-free impedimetric immunoassay for trace levels of polychlorinated biphenyls in insulating oil.

    PubMed

    Date, Yasumoto; Aota, Arata; Sasaki, Kazuhiro; Namiki, Yukie; Matsumoto, Norio; Watanabe, Yoshitomo; Ohmura, Naoya; Matsue, Tomokazu

    2014-03-18

    A rapid, ultrasensitive, and practical label-free impedimetric immunoassay for measuring trace levels of total polychlorinated biphenyls (PCBs) in insulating oil was developed. First, we developed a novel monoclonal antibody (RU6F9) for PCBs by using a designed immunogen and characterized its binding affinity for a commercial mixtures of PCBs and its main congeners. A micro comblike gold electrode was fabricated, and the antibody was covalently immobilized on the electrode through a self-assembled monolayer formed by dithiobis-N-succinimidyl propionate. The antigen-binding event on the surface of the functionalized electrode was determined as the change in charge transfer resistance by using electrochemical impedance spectroscopy. The resulting impedimetric immunoassay in aqueous solution achieved a wide determination range (0.01-10 μg/L) and a low detection limit (LOD) of 0.001 μg/L, which was 100-fold more sensitive than a conventional flow-based immunoassay for PCBs. By combining the impedimetric immunoassay with a cleanup procedure for insulating oil utilizing a multilayer cleanup column followed by DMSO partitioning, an LOD of 0.052 mg/kg-oil was achieved, which satisfied the Japanese regulation criterion of 0.5 mg/kg-oil. Finally, the immunoassay was employed to determine total PCB levels in actual used insulating oils (n = 33) sampled from a used transformer containing trace levels of PCBs, and the results agreed well with the Japanese official method (HRGC/HRMS). PMID:24528234

  9. High-performance UV-curable epoxy resin-based microarray and microfluidic immunoassay devices.

    PubMed

    Yu, Ling; Liu, Yingshuai; Gan, Ye; Li, Chang Ming

    2009-06-15

    Immunoassay devices including microarray and microfluidic systems were fabricated with an UV-curable resin by a new economic approach, which can not only simply produce a 3-dimensional (3D) patterned structure, but also simultaneously introduce functional epoxide groups for efficient protein immobilization. The performance of the epoxy resin-based microarray was improved by optimization of printing buffer, probe concentration, and immobilization time, showing a detection dynamic range of 5 orders of magnitude and a limit of detection (LOD) of 10 pg mL(-1) for immunoglobulin G (IgG). The developed microfluidic immunoassay device demonstrates a LOD of 100 pg mL(-1) for IL-5 detection. The device can also be used to colorimetrically detect proteins via naked human eyes for immunoassays. This work provides a simple and inexpensive method to fabricate a sensitive immunoassay device, especially a 3D microfluidic system, which has great potential to develop a portable immunoassay device via human eye detection for point-of-care service and/or high throughput screening of infectious diseases. PMID:19346122

  10. Molecular characterization of GYPB and RH in donors in the American Rare Donor Program.

    PubMed

    Vege, S; Westhoff, C M

    2006-01-01

    Transfusion of patients with sickle cell disease (SCD) has been a challenge in clinical transfusion medicine, especially when the required donor RBCs must be U- and negative for high-prevalence Rh phenotypes (hr(B), hr(S)). It is now possible to genotype donors to identify or confirm Uvar and U- phenotypes, as well as Rh hr(B)- and hrS- phenotypes, and to characterize the different RH backgrounds found in these donors. In a preliminary study of donors registered in the American Rare Donor Program, twelve different RH backgrounds were identified in eighteen hr(B)- or hr(S)- donors. These results, summarized in the current report, confirm the heterogeneous nature of these phenotypes and are relevant for selection of donor units for patients with antibodies to high-prevalence Rh antigens. Not all phenotypically similar units will be compatible, and matching the Rh genotype of the donor to the patient is important to prevent further Rh sensitization. Most donors referred were hr(B)- and carry at least one hybrid RHD-CE(3-7)-D gene that encodes a variant C antigen linked to RHCE*ceS that encodes the VS+V- phenotype. Surprisingly, the majority of donors were heterozygous, some even carrying conventional alleles, suggesting that the loss of expression of the hr(B) epitopes on RBCs is a dominant phenotype. Although antigen-matching of patients with SCD with donors for C, E, and K antigens has decreased the incidence of alloimmunization, some patients still become immunized to Rh antigens, indicating the units were not truly matched. RH genotyping can identify those patients with SCD who carry RH alleles that encode altered C, e, or D who are at risk for production of "apparent auto" and alloantibodies to Rh antigens. RH genotyping of alloimmunized patients with SCD, partnered with genotyping of donors, can identify compatible units that would also eliminate the risk of further Rh alloimmunization. PMID:17105364

  11. Predictors of donor follow-up after living donor liver transplantation.

    PubMed

    Brown, Robert S; Smith, Abigail R; Dew, Mary Amanda; Gillespie, Brenda W; Hill-Callahan, Peg; Ladner, Daniela P

    2014-08-01

    Donor safety in living liver donation is of paramount importance; however, information on long-term outcomes is limited by incomplete follow-up. We sought to ascertain factors that predicted postdonation follow-up in 456 living liver donors in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study. Completed donor follow-up was defined as physical, phone, or laboratory contact at a given time point. Univariate and multivariate mixed effects logistic regression models, using donor and recipient demographic and clinical data and donor quality-of-life data, were developed to predict completed follow-up. Ninety percent of the donors completed their follow-up in the first 3 months, and 83% completed their follow-up at year 1; rates of completed follow-up ranged from 57% to 72% in years 2 to 7 and from 41% to 56% in years 8 to 10. The probability of completed follow-up in the first year was higher for white donors [odds ratio (OR) = 3.27, 95% confidence interval (CI) = 1.25-8.58] but lower for donors whose recipients had hepatitis C virus or hepatocellular carcinoma (OR = 0.34, 95% CI = 0.17-0.69). After the first year, an older age at donation predicted more complete follow-up. There were significant center differences at all time points (OR range = 0.29-10.11), with center variability in both returns for in-center visits and the use of phone/long-distance visits. Donor follow-up in the first year after donation was excellent but decreased with time. Predictors of follow-up varied with the time since donation. In conclusion, adapting best center practices (enhanced through the use of telephones and social media) to maintain contact with donors represents a significant opportunity to gain valuable information about long-term donor outcomes. PMID:24824858

  12. Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India

    PubMed Central

    Chaurasia, Rahul; Rout, Diptiranjan; Zaman, Shamsuz; Chatterjee, Kabita; Pandey, Hem Chandra; Maurya, Abhishek Kumar

    2016-01-01

    Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions. PMID:26904124

  13. Recent advance in living donor liver transplantation.

    PubMed

    Hashikura, Yasuhiko; Kawasaki, Seiji; Miyagawa, Shinichi; Terada, Masaru; Ikegami, Toshihiko; Nakazawa, Yuichi; Urata, Koichi; Chisuwa, Hisanao; Ogino, Shiro; Makuuchi, Masatoshi

    2002-02-01

    Living donor liver transplantation (LDLT)has been performed in more than 2000 cases around the world. This procedure is considered to have certain advantages over cadaveric liver transplantation, because detailed preoperative evaluation of the donor liver is possible and superior graft quality is available. The indication has recently been widened to include adult patients. The results of LDLT have been reported to be very good. In this article,several considerations on LDLT,including living donor selection and application to adult patients, are discussed. Between June 1990 and March 2001, 143 patients underwent LDLT at Shinshu University Hospital. During this period, 160 patients were determined to be candidates for liver transplantation in our institution, and 185 candidates were evaluated as potential donors for these patients. Thirty-eight of 185 donor candidates were excluded for reasons including liver dysfunction and withdrawal of consent. The recipients included 60 adults, 50 (83%) of whom are currently alive. Taking into account the worldwide shortage of cadaveric organ donation,the importance of LDLT will probably never diminish. This procedure should be established on the basis of profound consideration of donor safety as well as accumulated expertise of hepatobiliary surgery. PMID:11865355

  14. Living donor transplant: wider selection criteria.

    PubMed

    Splendiani, G; Cipriani, S; Valeri, M; Torlone, N; Vega, A; Tullio, T; Condò, S; Dominijanni, S; Casciani, C U

    2004-04-01

    The availability of cadaveric donor organs is insufficient for actual needs. The organ demand increases by 20% per year. Living donor transplant (LDT) may be a valid therapeutical alternative provided one uses proper criteria. LDT provides many advantages, like improved patient and organ survival, short waiting time, and the possibility to carefully plan the procedure. Potential risks include perioperative mortality and renal dysfunction in the kidney donor. At present, kidney LDTs in Italy represent 8% of the total, with an organ survival rate of 97% after 1 year (vs 93% for cadaveric transplants) and donors mortality rate of almost null. Most LDTs are performed from kinsmen. Presently, law no. 458, 26 June 1967, is in force in Italy for kidney LDT and law no. 453, 16 December 1999, for liver LDT. The foundations of LDT are, of course, the recipient's condition, the donor's motivation, and the altruism of the donation. It is desirable that in the future an increasing number of LDT be performed, supported by a careful, widespread health education regarding organ donation from living subjects and by the possibility to obtain insurance for the donor, which has been considered but never provided by actual laws. PMID:15110560

  15. Donor identification 'kills gamete donation'? A response.

    PubMed

    Allan, Sonia

    2012-12-01

    Two Australian government inquiries have recently called for the release of information to donor-conceived people about their gamete donors. A national inquiry, recommended 'as a matter of priority' that uniform legislation to be passed nationwide. A state-based inquiry argued that all donor-conceived people should have access to information and called for the enactment of retrospective legislation that would override donor anonymity. This paper responds to an opinion piece published in Human Reproduction in October 2012 by Professor Pennings in which he criticized such recommendations and questioned the motives of people that advocate for information release. I answer the arguments of Pennings, and argue that all parties affected by donor conception should be considered, and a compromise reached. The contact veto system is one such compromise. I discuss the education and support services recommended by the Victorian government and question Pennings' assertions that legislation enabling information release will lead to a decrease in gamete donation. Finally, I rebut Pennings' assertion that there is a 'hidden agenda' behind the call for information release. There is no such agenda in my work. If there is from others, then it is their discriminatory views that need to be addressed, not the move toward openness and honesty or the call for information by donor-conceived people. PMID:23034154

  16. Antibody characterization and immunoassays for palytoxin using an SPR biosensor.

    PubMed

    Yakes, Betsy Jean; DeGrasse, Stacey L; Poli, Mark; Deeds, Jonathan R

    2011-07-01

    Palytoxin (PLTX), a polyether marine toxin originally isolated from the zoanthid Palythoa toxica, is one of the most toxic non-protein substances known. Fatal poisonings have been linked to ingestion of PLTX-contaminated seafood, and effects in humans have been associated with dermal and inhalational exposure to PLTX containing organisms and waters. Additionally, PLTX co-occurrence with other well-characterized seafood toxins (e.g., ciguatoxins, saxitoxins, tetrodotoxin) has hindered direct associations of PLTX to seafood-borne illnesses. There are currently no validated methods for the quantitative detection of PLTX(s). As such, a well-characterized, robust, specific analytical technique is needed for the detection of PLTX(s) in source organisms, surrounding waters, and clinical samples. Surface plasmon resonance (SPR) biosensors are ideally suited for antibody characterization and quantitative immunoassay detection. Herein, we describe a newly developed SPR assay for PLTX. An anti-mouse substrate was used to characterize the kinetic values for a previously developed monoclonal anti-PLTX. The characterized antibody was then incorporated into a sensitive, rapid, and selective PLTX assay. Buffer type, flow rate, analyte-binding time, and regeneration conditions were optimized for the antibody-PLTX system. Cross-reactivity to potentially co-occurring seafood toxins was also evaluated. We show that this optimized assay is capable of measuring low- to sub-ng/mL PLTX levels in buffer and two seafood matrices (grouper and clam). Preliminary results indicate that this SPR biosensor assay allows for (1) rapid characterization of antibodies and (2) rapid, sensitive PLTX concentration determination in seafood matrices. Method development information contained herein may be broadly applied to future PLTX detection and/or antibody characterization efforts. PMID:21523328

  17. Monoclonal IgA Antibodies for Aflatoxin Immunoassays

    PubMed Central

    Ertekin, Özlem; Pirinçci, Şerife Şeyda; Öztürk, Selma

    2016-01-01

    Antibody based techniques are widely used for the detection of aflatoxins which are potent toxins with a high rate of occurrence in many crops. We developed a murine monoclonal antibody of immunoglobulin A (IgA) isotype with a strong binding affinity to aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1). The antibody was effectively used in immunoaffinity column (IAC) and ELISA kit development. The performance of the IACs was compatible with AOAC performance standards for affinity columns (Test Method: AOAC 991.31). The total binding capacity of the IACs containing our antibody was 111 ng, 70 ng, 114 ng and 73 ng for AFB1, AFB2, and AFG1 andAFG2, respectively. Furthermore, the recovery rates of 5 ng of each AF derivative loaded to the IACs were determined as 104.9%, 82.4%, 85.5% and 70.7% for AFB1, AFB2, AFG1 and AFG2, respectively. As for the ELISA kit developed using non-oriented, purified IgA antibody, we observed a detection range of 2–50 µg/L with 40 min total test time. The monoclonal antibody developed in this research is hitherto the first presentation of quadruple antigen binding IgA monoclonal antibodies in mycotoxin analysis and also the first study of their utilization in ELISA and IACs. IgA antibodies are valuable alternatives for immunoassay development, in terms of both sensitivity and ease of preparation, since they do not require any orientation effort. PMID:27187470

  18. Replacing antibodies with aptamers in lateral flow immunoassay.

    PubMed

    Chen, Ailiang; Yang, Shuming

    2015-09-15

    Aptamers have been identified against various targets as a type of chemical or nucleic acid ligand by systematic evolution of ligands by exponential enrichment (SELEX) with high sensitivity and specificity. Aptamers show remarkable advantages over antibodies due to the nucleic acid nature and target-induced structure-switching properties and are widely used to design various fluorescent, electrochemical, or colorimetric biosensors. However, the practical applications of aptamer-based sensing and diagnostics are still lagging behind those of antibody-based tests. Lateral flow immunoassay (LFIA) represents a well established and appropriate technology among rapid assays because of its low cost and user-friendliness. The antibody-based platform is utilized to detect numerous targets, but it is always hampered by the antibody preparation time, antibody stability, and effect of modification on the antibody. Seeking alternatives to antibodies is an area of active research and is of tremendous importance. Aptamers are receiving increasing attention in lateral flow applications because of a number of important potential performance advantages. We speculate that aptamer-based LFIA may be one of the first platforms for commercial use of aptamer-based diagnosis. This review first gives an introduction to aptamer including the selection process SELEX with its focus on aptamer advantages over antibodies, and then depicts LFIA with its focus on aptamer opportunities in LFIA over antibodies. Furthermore, we summarize the recent advances in the development of aptamer-based lateral flow biosensing assays with the aim to provide a general guide for the design of aptamer-based lateral flow biosensing assays. PMID:25912679

  19. Monoclonal IgA Antibodies for Aflatoxin Immunoassays.

    PubMed

    Ertekin, Özlem; Pirinçci, Şerife Şeyda; Öztürk, Selma

    2016-01-01

    Antibody based techniques are widely used for the detection of aflatoxins which are potent toxins with a high rate of occurrence in many crops. We developed a murine monoclonal antibody of immunoglobulin A (IgA) isotype with a strong binding affinity to aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1). The antibody was effectively used in immunoaffinity column (IAC) and ELISA kit development. The performance of the IACs was compatible with AOAC performance standards for affinity columns (Test Method: AOAC 991.31). The total binding capacity of the IACs containing our antibody was 111 ng, 70 ng, 114 ng and 73 ng for AFB1, AFB2, and AFG1 andAFG2, respectively. Furthermore, the recovery rates of 5 ng of each AF derivative loaded to the IACs were determined as 104.9%, 82.4%, 85.5% and 70.7% for AFB1, AFB2, AFG1 and AFG2, respectively. As for the ELISA kit developed using non-oriented, purified IgA antibody, we observed a detection range of 2-50 µg/L with 40 min total test time. The monoclonal antibody developed in this research is hitherto the first presentation of quadruple antigen binding IgA monoclonal antibodies in mycotoxin analysis and also the first study of their utilization in ELISA and IACs. IgA antibodies are valuable alternatives for immunoassay development, in terms of both sensitivity and ease of preparation, since they do not require any orientation effort. PMID:27187470

  20. Surveillance of Fungal Allergic Sensitization Using the Fluorescent Halogen Immunoassay

    PubMed Central

    Green, Brett J.; Tovey, Euan R.; Beezhold, Donald H.; Perzanowski, Matthew S.; Acosta, Luis M.; Divjan, Adnan I.; Chew, Ginger L.

    2010-01-01

    SUMMARY Objective Conidia derived from a small number of common fungal genera are widely accepted as the etiological agents responsible for fungal allergic sensitization. The contribution of fungal conidia, spores, airborne hyphae, and subcellular fragments from other uncharacterized fungal genera remains unclear. In this proof-of-concept study, we examined the composition of mycoaerosols that atopic women were exposed and sensitized to in their own indoor environment using the fluorescent halogen immunoassay (fHIA). Patients and Methods Mycoaerosols were collected onto mixed cellulose ester protein binding membranes (PBMs) for 30 minutes with volumetric air sampling pumps. The PBMs were laminated with an adhesive cover slip and indirectly immunostained with individual patient serum IgE using the fHIA. Samples were examined using confocal laser scanning microscopy and immunostained particles were expressed as a percentage of total particles. Results All air samples contained a broad spectrum of fungal spores, conidia, hyphae, and other fungal particulates. Airborne concentrations varied between individual study participant environments. Positively immunostained conidia belonging to moniliaceous amerospores, Cladosporium, Alternaria, and many unknown species were observed in the majority of air samples. Other fungal genera including Bipolaris, Curvularia, Pithomyces, and Stachybotrys, in addition to, ascospore genera and dematiaceous hyphal fragments released detectable allergen. Twelve percent of all fHIA haloes quantified in the analysis were directed towards fungal particles. No immunostaining was detected to conidia belonging to Epicoccum, Fusarium, and Spegazzinia species. Conclusion In addition to characterized fungal aeroallergens, we observed a wider composition of fungi that bound human IgE. Field surveillance studies that utilize immunodiagnostic techniques such as the fHIA will provide further insight into the diversity of fungi that function as

  1. A novel immunoassay for quantitative drug abuse screening in serum.

    PubMed

    Schumacher, Sarah; Seitz, Harald

    2016-09-01

    An immunoassay was established which enables a reliable quantification of serological drug samples. The assay is based on a competitive ELISA. In total nine drugs (amphetamine, methamphetamine, 3,4-methylenedioxy-methamphetamine (MDMA), tetrahydrocannabinol (THC), phencyclidine (PCP), methadone, morphine, cocaine and benzoylecgonine) were tested. All reagents had to pass through a stringent validation process. Within the established test for three out of the nine drugs no cross-reactivity with any tested compounds, e.g. serum, other antibodies or chemically related molecules was detectable for the tested antibodies. Furthermore, a sensitive and selective detection was possible, even in the presence of up to 9 drugs or of various anti-drug antibodies. After exclusion of cross-reactivities antibodies against three drugs (methadone, MDMA, benzoylecgonine) were validated, which allowed a specific and sensitive quantification. For the competitive measurements CVs in the range of 2-17% could be reached with LLOQs of 10ng/mL and LODs of 150ng/mL for methadone, 250ng/mL for MDMA and 400ng/mL for benzoylecgonine. Anonymized serum samples (n=10) provided by the office of criminal investigation Berlin were analyzed for verification purposes. Evaluation of these data showed a correlation (CV) of ≈0.9 with standard GC-MS methods. A miniaturization on microarray was possible by using the anti-MDMA antibody for the detection of MDMA in serum. The microarray increased the through-put drastically and enabled the simultaneous quantification of various drugs. PMID:27343723

  2. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

    PubMed Central

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-01-01

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  3. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections.

    PubMed

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-06-24

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  4. Sperm donors describe the experience of contact with their donor-conceived offspring.

    PubMed

    Hertz, R; Nelson, M K; Kramer, W

    2015-01-01

    This study explores the attitudes and experiences of 57 sperm donors who responded to a survey posted online in the United States and indicated that they had had contact with their donor-conceived offspring or the parents of their donor-conceived offspring. On average, 18 years had elapsed since the respondents donated sperm. In the interim between donating and having contact with offspring, most had become curious about their offspring. Most made contact through a bank or online registry. Most respondents had communicated with at least one offspring at least once and most had exchanged photos with offspring. Approximately two-thirds had met in person once; the same proportion had communicated over email or text. Other forms of communication were less common. Almost half of the respondents now considered their donor-conceived offspring to be like a family member. At the same time, donors are respectful of the integrity of the family in which their offspring were raised. Donors with contact are open to having their partners and children know their donor-conceived offspring. Although contact is generally positive, donors report that establishing boundaries and defining the relationship can be very difficult. Some donors also urge those who are thinking of donating to consider the consequences and some suggest avoiding anonymity. There were no significant differences in attitudes and experiences between those who donated anonymously and those who had been identity-release for their offspring when they turned 18. PMID:26175887

  5. Expanding the live kidney donor pool: ethical considerations regarding altruistic donors, paired and pooled programs.

    PubMed

    Patel, Shaneel Rajendra; Chadha, Priyanka; Papalois, Vassilios

    2011-06-01

    In renal transplant, there is a well-known deficiency in organ supply relative to demand. Live donation provides superior results when compared with deceased donation including a better rate of graft success and fewer immunologic complications. This deficiency in organs leads to significant morbidity and mortality rates. Alternative avenues have been extensively explored that may expand the live donor pool. They include altruistic donation as well as paired and pooled exchange programs. Altruistic donation is a truly selfless act from a donor unknown to the recipient. Kidney paired donation involves 2 incompatible donor-recipient pairs swapping donors to produce compatibility. Pooled donation involves at least 2 pairs, and can take the form of domino chains in which altruistic input sets up a chain of transplants, in which each recipient's incompatible donor makes a donation for the next recipient. Despite application of these various methods, there lie extensive ethical issues surrounding them. Misconceptions frequently occur; for instance, the perceived benefit that donating an organ to a loved one is greater for a related donor than for an altruistic one. Additionally, it is frequently believed that immunologic incompatibility offers coerced donors liberation from surgery, and that overcoming these barriers by introducing exchange programs provides vulnerable donors less protection. This article explores these and other complex ethical issues surrounding the various methods of expanding the donor pool. The authors offer opinions that challenge the ethical issues and attempt to overcome those views that hinder progress in the field. PMID:21649566

  6. Sperm donors describe the experience of contact with their donor-conceived offspring

    PubMed Central

    Hertz, R.; Nelson, M.K.; Kramer, W.

    2015-01-01

    This study explores the attitudes and experiences of 57 sperm donors who responded to a survey posted online in the United States and indicated that they had had contact with their donor-conceived offspring or the parents of their donor-conceived offspring. On average, 18 years had elapsed since the respondents donated sperm. In the interim between donating and having contact with offspring, most had become curious about their offspring. Most made contact through a bank or online registry. Most respondents had communicated with at least one offspring at least once and most had exchanged photos with offspring. Approximately two-thirds had met in person once; the same proportion had communicated over email or text. Other forms of communication were less common. Almost half of the respondents now considered their donor-conceived offspring to be like a family member. At the same time, donors are respectful of the integrity of the family in which their offspring were raised. Donors with contact are open to having their partners and children know their donor-conceived offspring. Although contact is generally positive, donors report that establishing boundaries and defining the relationship can be very difficult. Some donors also urge those who are thinking of donating to consider the consequences and some suggest avoiding anonymity. There were no significant differences in attitudes and experiences between those who donated anonymously and those who had been identity-release for their offspring when they turned 18. PMID:26175887

  7. How Organ Donors are Different from Non-donors: Responsibility, Barriers, and Religious Involvement.

    PubMed

    Range, Lillian M; Brazda, Geoffrey F

    2015-12-01

    To see if religious involvement, previously linked to various health behaviors, was linked to organ donation, 143 ethnically diverse undergraduates stated whether they were registered donors (53% were), and completed measures of organ donation attitudes and religious involvement. Compared with non-donors, donors reported fewer barriers, more family responsibility, and more willingness to receive donor organs, but were not different in religious involvement. Even in 2014, when being a "good Samaritan" by agreeing to organ donation is as easy as checking one box on a driver's license application, religious involvement does not seem to be a factor in checking this box. PMID:25524413

  8. Evaluation of the siemens HIV antigen-antibody immunoassay.

    PubMed

    Vallefuoco, Luca; Aden Abdi, Fatima; Sorrentino, Rosanna; Spalletti-Cernia, Daniela; Mazzarella, Claudia; Barbato, Sara; Perna, Enzo; Buffolano, Wilma; Di Nicuolo, Giuseppe; Portella, Giuseppe

    2014-01-01

    Fourth-generation assays for the simultaneous detection of human immunodeficiency virus (HIV) antigen and antibodies are available on the international market and are currently used for blood donor screening and for HIV diagnosis. In this study we evaluated the performance of the novel automated fourth-generation ADVIA Centaur® HIV Ag/Ab Combo assay. The assay detected seroconversion at the same bleed or at least one bleed earlier in panels with respect to other assays and showed a detection efficacy equal to those of other assays in a low-titer panel. Samples obtained from blood donors (n = 2,778) or from HIV-positive patients (HIV-1 B subtype, n = 82; non-B subtype, n = 71) were also tested, showing a good correlation with other fourth-generation assays. We assessed the performance of 3 fourth-generation assays for detecting in utero transmitted anti-HIV antibodies and found a more specific detection efficiency with the ADVIA Centaur HIV Ag/Ab Combo assay compared to the other fourth-generation assays. PMID:24557036

  9. Day-of-surgery rejection of donors in living donor liver transplantation

    PubMed Central

    Hegab, Bassem; Abdelfattah, Mohamed Rabei; Azzam, Ayman; Mohamed, Hazem; Hamoudi, Waleed Al; Alkhail, Faisal Aba; Bahili, Hamad Al; Khalaf, Hatem; Sofayan, Mohammed Al; Sebayel, Mohammed Al

    2012-01-01

    AIM: To study diagnostic laparoscopy as a tool for excluding donors on the day of surgery in living donor liver transplantation (LDLT). METHODS: This study analyzed prospectively collected data from all potential donors for LDLT. All of the donors were subjected to a three-step donor evaluation protocol at our institution. Step one consisted of a clinical and social evaluation, including a liver profile, hepatitis markers, a renal profile, a complete blood count, and an abdominal ultrasound with Doppler. Step two involved tests to exclude liver diseases and to evaluate the donor’s serological status. This step also included a radiological evaluation of the biliary anatomy and liver vascular anatomy using magnetic resonance cholangiopancreatography and a computed tomography (CT) angiogram, respectively. A CT volumetric study was used to calculate the volume of the liver parenchyma. Step three included an ultrasound-guided liver biopsy. Between November 2002 and May 2009, sixty-nine potential living donors were assessed by open exploration prior to harvesting the planned part of the liver. Between the end of May 2009 and October 2010, 30 potential living donors were assessed laparoscopically to determine whether to proceed with the abdominal incision to harvest part of the liver for donation. RESULTS: Ninety-nine living donor liver transplants were attempted at our center between November 2002 and October 2010. Twelve of these procedures were aborted on the day of surgery (12.1%) due to donor findings, and eighty-seven were completed (87.9%). These 87 liver transplants were divided into the following groups: Group A, which included 65 transplants that were performed between November 2002 and May 2009, and Group B, which included 22 transplants that were performed between the end of May 2009 and October 2010. The demographic data for the two groups of donors were found to match; moreover, no significant difference was observed between the two groups of donors with

  10. In-field assessment of chemical high explosives using immunoassay techniques

    SciTech Connect

    Hardy, D.J.; Crossley, D.B.; O`Connell, M.S.

    1995-12-31

    Base realignment and weapons complex reconfiguration have prompted closure of former military related properties. As a result, chemical high explosives in environmental media are encountered with greater frequency during accelerated site characterization activities. The DOE`s Pantex nuclear weapons production/disassembly facility in Amarillo, Texas has observed nitroaromatic and nitramine compounds in soil and groundwater. Recognizing that phases characterization programs are time consuming and expensive, Pantex has employed compound specific immunoassay screening techniques to semi-quantitatively assess high explosive contamination in environmental media. As a result of using immunoassay techniques at over 500 sample locations, Pantex has achieved significant benefits corollary to reduced analytical expenses and timeframes, waste generation and management expenditures, field mobilization, and site characterization timeframes. Pantex Plant concludes that the use of immunoassay field screening of samples for chemical high explosives results in accelerated site characterization at a decreased expense while maintaining quality protocols and worker protection.

  11. Optimizing Two-Color Semiconductor Nanocrystal Immunoassays in Single Well Microtiter Plate Formats

    PubMed Central

    Sapsford, Kim E.; Spindel, Samantha; Jennings, Travis; Tao, Guoliang; Triulzi, Robert C.; Algar, W. Russ; Medintz, Igor L.

    2011-01-01

    The simultaneous detection of two analytes, chicken IgY (IgG) and Staphylococcal enterotoxin B (SEB), in the single well of a 96-well plate is demonstrated using luminescent semiconductor quantum dot nanocrystal (NC) tracers. The NC-labeled antibodies were prepared via sulfhydryl-reactive chemistry using a facile protocol that took <3 h. Dose response curves for each target were evaluated in a single immunoassay format and compared to Cy5, a fluorophore commonly used in fluorescent immunoassays, and found to be equivalent. Immunoassays were then performed in a duplex format, demonstrating multiplex detection in a single well with limits of detection equivalent to the single assay format: 9.8 ng/mL chicken IgG and 7.8 ng/mL SEB. PMID:22164051

  12. Ultra-sensitive immunoassay biosensors using hybrid plasmonic-biosilica nanostructured materials.

    PubMed

    Yang, Jing; Zhen, Le; Ren, Fanghui; Campbell, Jeremy; Rorrer, Gregory L; Wang, Alan X

    2015-08-01

    We experimentally demonstrate an ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles. As the nature-created photonic crystal structures, diatoms have been adopted to enhance surface plasmon resonances of metal nanoparticles on the surfaces of diatom frustules and to increase the sensitivity of surface-enhanced Raman scattering (SERS). In this study, a sandwich SERS immunoassay is developed based on the hybrid plasmonic-biosilica nanostructured materials that are functionalized with goat anti-mouse IgG. Our experimental results show that diatom frustules improve the detection limit of mouse IgG to 10 pg/mL, which is ˜100× better than conventional colloidal SERS sensors on flat glass. Ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles. PMID:25256544

  13. Immunoassay based water quality analysis: A new tool for drinking water supply management

    SciTech Connect

    Kostyshyn, C.R.; Brown, W.; Hervey, E.; Hull, C.

    1996-11-01

    The recent availability of enzyme-linked immunosorbent assay (ELISA) tests for the analysis of organic environmental contaminants provides drinking water utility managers and operators with a new tool for managing treatment operations and monitoring source watersheds. Immunoassay technology permits rapid, inexpensive and accurate in-plant testing of many SDWA regulated organic contaminants at concentrations well below established MCL`s. Analytical testing which would not be practicable due to the high cost or long turnaround time limitations of conventional testing methods is now being performed using immunoassay based analysis. Water quality data generated using immunoassay based methods are being utilized by drinking water utilities as an integral part of source watershed management programs, process operations optimization efforts, pro-active raw and finished water testing programs, and flood and incident response management.

  14. Enabling Rapid and Specific Surface-Enhanced Raman Scattering Immunoassay Using Nanoscaled Surface Shear Forces.

    PubMed

    Wang, Yuling; Vaidyanathan, Ramanathan; Shiddiky, Muhammad J A; Trau, Matt

    2015-06-23

    A rapid and simple approach is presented to address two critical issues of surface-enhanced Raman scattering (SERS)-based immunoassay such as removal/avoiding nonspecific adsorption and reducing assay time. The approach demonstrated involves rationally designed fluorophore-integrated gold/silver nanoshells as SERS nanotags and utilizes alternative current electrohydrodynamic (ac-EHD)-induced nanoscaled surface shear forces to enhance the capture kinetics. The assay performance was validated in comparison with hydrodynamic flow and conventional immunoassay-based devices. These nanoscaled physical forces acting within nanometer distances from the electrode surface enabled rapid (40 min), sensitive (10 fg/mL), and highly specific detection of human epidermal growth factor receptor 2 in breast cancer patient samples. We believe this approach presents potential for the development of rapid and sensitive SERS immunoassays for routine clinical diagnosis. PMID:25978642

  15. A SERS-based microfluidic immunoassay using an in-situ synthesized gold substrate

    NASA Astrophysics Data System (ADS)

    Fan, Kequan; Wang, Zhuyuan; Wu, Lei; Zong, Shenfei; Cui, Yiping

    2015-05-01

    A sensitive SERS (surface-enhanced Raman scattering)-based immunoassay in microfluidic system has been developed with in-situ synthesis of gold substrate and immune reporter named as 4MBA (4-Mercaptobenzoic acid)-labeled immuno-Ag aggregates. The gold substrate was fabricated simply by introducing the hydrogen tetrachloroaurate (III) trihydrate (HAuCl4) solution to microchannels using a microfluidic pump. It was found that the obtained deposited gold nanoparticles were uniform in size and shape. Then the sandwich immunoassays were performed using the gold substrates based on SERS signals. In the immunoassay, the gold nanoparticles decorated surface was modified with certain antibodies to recognize the specific kind of antigen, which was flowed through the microfluidic channel afterwards. Then 4MBA-labeled immuno-Ag aggregates were employed as the SERS probes to quantitatively detect the antigen. The experimental results showed a good specificity and limit of detection (LOD) about 1 ng/mL.

  16. Rapid and Sensitive Chemiluminescent Enzyme Immunoassay for the Determination of Neomycin Residues in Milk.

    PubMed

    Luo, Peng Jie; Zhang, Jian Bo; Wang, Hua Li; Chen, Xia; Wu, Nan; Zhao, Yun Feng; Wang, Xiao Mei; Zhang, Hong; Zhang, Ji Yue; Zhu, Lei; Jiang, Wen Xiao

    2016-05-01

    Immunoassays greatly contribute to veterinary drug residue analysis. However, there are few reports on detecting neomycin residues by immunoassay. Here, a rapid and sensitive chemiluminescent enzyme immunoassay (CLIEA) was successfully developed for neomycin residue analysis. CLIEA demonstrated good cross-reactivity for neomycin, and the IC50 value was 2.4 ng/mL in buffer. The average recovery range was 88.5%-105.4% for spiked samples (10, 50, and 100 μg/kg), and the coefficient of variation was in the range of 7.5%-14.5%. The limit of detection of CLEIA was 9.4 μg/kg, and this method was compared with the liquid chromatography-tandem mass spectrometry method using naturally contaminated samples, producing a correlation coefficient of >0.95. We demonstrate a reliable CLIEA for the rapid screening of neomycin in milk. PMID:27353712

  17. Donor Deferral Rates after the Implementation of a New German Blood Donor Questionnaire

    PubMed Central

    Müller-Steinhardt, Michael; Weidmann, Christian; Wiesneth, Markus; Weck, Eberhard; Seifried, Erhard; Brade, Joachim; Klüter, Harald

    2012-01-01

    Background The implementation of a new national German blood donor questionnaire was proposed to improve donor and recipient safety. Methods We compared deferral/exclusion rates of whole blood donors before (May 2010, n = 64,735) and after (May 2011, n = 71,687) the implementation of a new blood donor questionnaire. Considering seasonal variations, analysis was performed with respect to collection site (mobile vs. fixed), sex, donor status (first-time vs. repeat), age, and the frequencies of sexual risk behavior and other reasons for deferral. Results We observed a statistically significant increase (p < 0.001) of the overall deferral/exclusion rate from 6.2 to 8.1%, irrespective of type of collection site (fixed: from 6.0 to 8.5%; mobile: from 6.2 to 8.0%), sex (females: from 7.5 to 9.9%; males: from 5.1 to 6.6%), donor status (first-time donors: from 19.7 to 24.7%; repeat donors: from 4.6 to 6.3%) or age (18–29 years: from 9.1 to 11.7%; 60–71 years: from 5.1 to 6.6%). Confidential self-exclusion increased from 0.08 to 0.14% (p < 0.001). Besides risk behavior, various medical reasons could be identified that explain this increase. Conclusions The new blood donor questionnaire resulted in an increased deferral/exclusion of all donor groups. Thus the impact on future blood supply must be considered carefully, and long-term studies and investigation of donor acceptance will be needed. PMID:22896762

  18. The willed body donor interview project: medical student and donor expectations.

    PubMed

    Bohl, Michael; Holman, Alexis; Mueller, Dean A; Gruppen, Larry D; Hildebrandt, Sabine

    2013-01-01

    The Anatomical Donations Program at the University of Michigan Medical School (UMMS) has begun a multiphase project wherein interviews of donors will be recorded and later shown to medical students who participate in the anatomical dissection course. The first phase of this project included surveys of both current UMMS medical students and donors concerning their perceptions of such a program. A five-question survey administered via Qualtrics software was electronically mailed to all current medical students at UMMS, and a survey was mailed to registered and potential donors requesting information from the UMMS on anatomical donations. A total of 224 medical student responses (response rate 33%) and 54 donor responses (response rate 27%) were received. Seventy-four percent of students and 81% of donors reported they would participate in this program if it existed. Students and donors supported the implementation of this program for varying reasons, though many felt strongly they would not want to participate in a donor interview program. These qualitative results support those of previous studies that show a majority of students desire a closer personal relationship with the donor, and these are the first results to be reported on donor perceptions of a donor interview program. Although many students and donors are in favor of instituting this program, others feel strongly that such an experience could be traumatic. The causes of these differing reactions need to be further explored, and the opinions of those who object to this study will be respected by maintaining voluntary participation in future phases of this study. PMID:23109299

  19. TT virus among blood donors in Alexandria.

    PubMed

    Hashish, Mona H; El-Barrawy, Mohamed A; Mahmoud, Ola A; Abdel Rahman, Nader W

    2005-01-01

    TTV is a non enveloped, single-stranded, circular- DNA virus that has been assigned to the Family Circiniviridae. The primary mode of TTV transmission was proposed to be transfusion (and hence its name). Little is known about the clinical significance and the natural history of TTV infection. Hence, responsibility of the virus for specific liver disease is still debated. In our study, we tested ninety five blood donors attending Kom EL-Decka regional blood bank in Alexandria for the presence of TTV DNA in their sera by PCR technique. The same samples were tested for ALT and AST levels by colorimetric technique and for HBsAg and anti-HCV by the ELISA technique. Out of the 95 blood donors, 46 (48.4%) had TTV DNA in their sera. None of the 95 blood donors included in this study was positive for HBsAg, while 22 (23.2%) were anti-HCV positive. Out of the 22 anti-HCV positive blood donors, 13 (59.1%) were TTV DNA positive, while out of the 73 anti-HCV negative blood donors, 33 (45.2%) had TTV DNA in their sera. There was no statistically significant difference between the prevalence of TTV DNA and anti-HCV in blood donors. No biochemical evidence of liver disease potentially linked to the TTV infection was observed in our blood donors who were TTV DNA positive. Furthermore, the occurrence of elevated serum AST and ALT was most often linked to HCV rather than TTV. PMID:17187747

  20. Using cheminformatics to predict cross reactivity of “designer drugs” to their currently available immunoassays

    PubMed Central

    2014-01-01

    Background A challenge for drug of abuse testing is presented by ‘designer drugs’, compounds typically discovered by modifications of existing clinical drug classes such as amphetamines and cannabinoids. Drug of abuse screening immunoassays directed at amphetamine or methamphetamine only detect a small subset of designer amphetamine-like drugs, and those immunoassays designed for tetrahydrocannabinol metabolites generally do not cross-react with synthetic cannabinoids lacking the classic cannabinoid chemical backbone. This suggests complexity in understanding how to detect and identify whether a patient has taken a molecule of one class or another, impacting clinical care. Methods Cross-reactivity data from immunoassays specifically targeting designer amphetamine-like and synthetic cannabinoid drugs was collected from multiple published sources, and virtual chemical libraries for molecular similarity analysis were built. The virtual library for synthetic cannabinoid analysis contained a total of 169 structures, while the virtual library for amphetamine-type stimulants contained 288 compounds. Two-dimensional (2D) similarity for each test compound was compared to the target molecule of the immunoassay undergoing analysis. Results 2D similarity differentiated between cross-reactive and non-cross-reactive compounds for immunoassays targeting mephedrone/methcathinone, 3,4-methylenedioxypyrovalerone, benzylpiperazine, mephentermine, and synthetic cannabinoids. Conclusions In this study, we applied 2D molecular similarity analysis to the designer amphetamine-type stimulants and synthetic cannabinoids. Similarity calculations can be used to more efficiently decide which drugs and metabolites should be tested in cross-reactivity studies, as well as to design experiments and potentially predict antigens that would lead to immunoassays with cross reactivity for a broader array of designer drugs. PMID:24851137

  1. Inter-laboratory Variability of Current Immunoassay Methods for Tacrolimus among Japanese Hospitals.

    PubMed

    Miura, Masatomo; Masuda, Satohiro; Egawa, Hiroto; Yuzawa, Kenji; Matsubara, Kazuo

    2016-08-01

    The aim of this study was to assess inter-hospital laboratory variability (coefficient of variation; CV) of immunoassay methods for tacrolimus and the comparability of control samples and results obtained by immunoassay measurements. One hundred seven hospital laboratories routinely performing therapeutic drug monitoring (TDM) of tacrolimus participated in the study. Thirteen spiked samples with known tacrolimus concentrations in the range of 0-26.0 ng/mL were prepared. Each spiked sample was analyzed according to the manufacturer's instructions using an affinity column-mediated immunoassay (ACMIA) on a Dimension(®) analyzer, the enzyme multiplied immunoassay technique (EMIT) on a Viva-E(®) analyzer, a chemiluminescent enzyme immunoassay (CLIA) on the Architect(®) system, and the electro-chemiluminescence immunoassay (ECLIA) on a cobas(®) analyzer. The 20% coefficient of variation values for the CLIA, ACMIA, EMIT, and ECLIA assays in the hospital laboratories were 1.82, 5.36, 4.59, and 0.89 ng/mL, respectively. CLIA and ECLIA had positive biases at concentrations of tacrolimus above 12 ng/mL relative to the spiked concentration, whereas the assay bias for ACMIA tended to be more negative at concentrations of tacrolimus above 6 ng/mL. EMIT had positive biases over the wide concentration range of 0.0-26.0 ng/mL (mean of mean errors 1.224). CLIA and ECLIA provided adequate precision at the target tacrolimus concentration of 3.0 ng/mL, whereas ACMIA and EMIT were unable to respond to target concentrations between 3.0 and 5.0 ng/mL for renal transplant recipients. Appropriate assessment of tacrolimus concentration by an assay having higher sensitivity, precision, and accuracy is necessary to ensure long-term survival of transplant recipients receiving tacrolimus. PMID:27263473

  2. Evaluation of the medically complex living kidney donor.

    PubMed

    Caliskan, Yasar; Yildiz, Alaattin

    2012-01-01

    Due to organ shortage and difficulties for availability of cadaveric donors, living donor transplantation is an important choice for having allograft. Live donor surgery is elective and easier to organize prior to starting dialysis thereby permitting preemptive transplantation as compared to cadaveric transplantation. Because of superior results with living kidney transplantation, efforts including the usage of "Medically complex living donors" are made to increase the availability of organs for donation. The term "Complex living donor" is probably preferred for all suboptimal donors where decision-making is a problem due to lack of sound medical data or consensus guidelines. Donors with advanced age, obesity, asymptomatic microhematuria, proteinuria, hypertension, renal stone disease, history of malignancy and with chronic viral infections consist of this complex living donors. This medical complex living donors requires careful evaluation for future renal risk. In this review we would like to present the major issues in the evaluation process of medically complex living kidney donor. PMID:22655169

  3. The infrared fingerprint signals of silica nanoparticles and its application in immunoassay

    NASA Astrophysics Data System (ADS)

    Ding, Yadan; Chu, Xueying; Hong, Xia; Zou, Peng; Liu, Yichun

    2012-01-01

    Infrared absorption properties of silica nanoparticles were studied. The transverse optical and the longitudinal optical phonon modes from the silica were proved to be the characteristic spectroscopic fingerprint signals. Based on this, a sandwich-structured immunoassay was performed, and the detection of the analyte (human IgG) was achieved by using biofunctional silica nanoparticles as infrared probes. The immunoassay based on Fourier transform infrared reflection absorption spectroscopy of silica nanoparticles shows significant value for potential applications in many areas, such as biomedicine, food safety, and waste treatment.

  4. Measurement of anti-Mullerian hormone: performances of a new ultrasensitive immunoassay.

    PubMed

    Gruson, Damien; Homsak, Evgenija

    2015-04-01

    The measurement of anti-Mullerian hormone (AMH) is relevant for the evaluation of primary ovarian insufficiency, success of assisted reproductive therapies, and also to support the diagnosis of polycystic ovary syndrome. Our study demonstrated excellent analytical performances for the Ansh Laboratories AMH immunoassay and an overall good agreement with the AMH Gen II assay. Nevertheless, the two AMH immunoassays are not using the same couple of antibodies and therefore not commutable and the definition of specific reference values and cut-point remains necessary. PMID:25575745

  5. Different Vancomycin Immunoassays Contribute to the Variability in Vancomycin Trough Measurements in Neonates

    PubMed Central

    Smits, Anne; Spriet, Isabel; Soldatovic, Ivan; Atkinson, Andrew; Bajcetic, Milica; Van Den Anker, John N.; Allegaert, Karel

    2016-01-01

    Substantial interassay variability (up to 20%) has been described for vancomycin immunoassays in adults, but the impact of neonatal matrix is difficult to quantify because of blood volume constraints in neonates. However, we provide circumstantial evidence for a similar extent of variability. Using the same vancomycin dosing regimens and confirming similarity in clinical characteristics, vancomycin trough concentrations measured by PETINIA (2011-2012, n = 400) were 20% lower and the mean difference was 1.93 mg/L compared to COBAS (2012–2014, n = 352) measurements. The impact of vancomycin immunoassays in neonatal matrix was hereby suggested, supporting a switch to more advanced techniques (LC-MS/MS).

  6. International rare donor panels: a review.

    PubMed

    Nance, S; Scharberg, E A; Thornton, N; Yahalom, V; Sareneva, I; Lomas-Francis, C

    2016-04-01

    International rare blood donor panels or registries are important in the consistent availability of rare blood for patients who need this scarce resource. In countries where it has been possible to commit resources to this effort and often where the need is great, donors have been entered into a registry. The ISBT leadership recognized the importance of this very challenging inventory management activity and created a Working Party to support it. Individual countries support the WHO International Rare Donor Panel by submitting their donors' phenotype or genotype information to be catalogued into the database. It is extremely important that this database be cultivated and grown. The contributing countries keep their list updated and supply the blood product as they can when requested. It is known that some blood types are extremely scarce worldwide and requests for these are particularly difficult to fulfil. Thus, it is important to have a protocol to identify and recruit donors with rare blood types. It is equally or perhaps more important to ensure that the patients who need the rare blood are being managed appropriately in the presence and absence of rare blood products being available. PMID:26689301

  7. The Effect of Donor Age on Corneal Transplantation Outcome: Results of the Cornea Donor Study

    PubMed Central

    2009-01-01

    Objective To determine whether graft survival over a 5-year follow-up period using corneal tissue from donors older than 65 years of age is similar to graft survival using corneas from younger donors. Design Multi-center prospective, double-masked, controlled clinical trial Participants 1090 subjects undergoing corneal transplantation for a moderate risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema); 11 subjects with ineligible diagnoses were not included Methods 43 participating eye banks provided corneas from donors in the age range of 12 to 75 with endothelial cell densities of 2300 to 3300 cells/mm2, using a random approach without respect to recipient factors. The 105 participating surgeons at 80 sites were masked to information about the donor cornea including donor age. Surgery and post-operative care were performed according to the surgeons’ usual routines. Subjects were followed for five years. Main Outcome Measures Graft failure, defined as a regraft or a cloudy cornea that was sufficiently opaque as to compromise vision for a minimum of three consecutive months. Results The 5-year cumulative probability of graft survival was 86% in both the <66.0 donor age group and the ≥66.0 donor age group (difference = 0%, upper limit of one-sided 95% confidence interval = 4%). In a statistical model with donor age as a continuous variable, there was not a significant relationship between donor age and outcome (P=0.11). Three graft failures were due to primary donor failure, 8 to uncorrectable refractive error, 48 to graft rejection, 46 to endothelial decompensation (23 of which had a prior, resolved episode of probable or definite graft rejection), and 30 to other causes. The distribution of the causes of graft failure did not differ between donor age groups. Conclusions Five-year graft survival for cornea transplants at moderate risk for failure is similar using corneas from donors ≥ 66.0 years and donors < 66.0 years. Surgeons and

  8. Bead-based microfluidic immunoassay for diagnosis of Johne's disease

    SciTech Connect

    Wadhwa, Ashutosh; Foote, Robert; Shaw, Robert W; Eda, Shigetoshi

    2012-01-01

    Microfluidics technology offers a platform for development of point-of-care diagnostic devices for various infectious diseases. In this study, we examined whether serodiagnosis of Johne s disease (JD) can be conducted in a bead-based microfluidic assay system. Magnetic micro-beads were coated with antigens of the causative agent of JD, Mycobacterium avium subsp. paratuberculosis. The antigen-coated beads were incubated with serum samples of JD-positive or negative serum samples and then with a fluorescently-labeled secondary antibody (SAB). To confirm binding of serum antibodies to the antigen, the beads were subjected to flow cytometric analysis. Different conditions (dilutions of serum and SAB, types of SAB, and types of magnetic beads) were optimized for a great degree of differentiation between the JD-negative and JD-positive samples. Using the optimized conditions, we tested a well-classified set of 155 serum samples from JD negative and JD-positive cattle by using the bead-based flow cytometric assay. Of 105 JD-positive samples, 63 samples (60%) showed higher antibody binding levels than a cut-off value determined by using antibody binding levels of JD-negative samples. In contrast, only 43-49 JD-positive samples showed higher antibody binding levels than the cut-off value when the samples were tested by commercially-available immunoassays. Microfluidic assays were performed by magnetically immobilizing a number of beads within a microchannel of a glass microchip and detecting antibody on the collected beads by laser-induced fluorescence. Antigen-coated magnetic beads treated with bovine serum sample and fluorescently-labeled SAB were loaded into a microchannel to measure the fluorescence (reflecting level of antibody binding) on the beads in the microfluidic system. When the results of five bovine serum samples obtained with the system were compared to those obtained with the flow cytometer, a high level of correlation (linear regression, r2 = 0.994) was

  9. Multiplex Serum Cytokine Immunoassay Using Nanoplasmonic Biosensor Microarrays

    PubMed Central

    Chen, Pengyu; Chung, Meng Ting; McHugh, Walker; Nidetz, Robert; Li, Yuwei; Fu, Jianping; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo

    2015-01-01

    Precise monitoring of the rapidly changing immune status during the course of a disease requires multiplex analysis of cytokines from frequently sampled human blood. However, the current lack of rapid, multiplex, and low volume assays makes immune monitoring for clinical decision-making (e.g., critically ill patients) impractical. Without such assays, immune monitoring is even virtually impossible for infants and neonates with infectious diseases and/or immune mediated disorders as access to their blood in large quantities is prohibited. Localized surface plasmon resonance (LSPR)-based microfluidic optical biosensing is a promising approach to fill this technical gap as it could potentially permit real-time refractometric detection of biomolecular binding on a metallic nanoparticle surface and sensor miniaturization, both leading to rapid and sample-sparing analyte analysis. Despite this promise, practical implementation of such a microfluidic assay for cytokine biomarker detection in serum samples has not been established primarily due to the limited sensitivity of LSPR biosensing. Here, we developed a high-throughput, label-free, multiarrayed LSPR optical biosensor device with 480 nanoplasmonic sensing spots in microfluidic channel arrays and demonstrated parallel multiplex immunoassays of six cytokines in a complex serum matrix on a single device chip while overcoming technical limitations. The device was fabricated using easy-to-implement, one-step microfluidic patterning and antibody conjugation of gold nanorods (AuNRs). When scanning the scattering light intensity across the microarrays of AuNR ensembles with dark-field imaging optics, our LSPR biosensing technique allowed for high-sensitivity quantitative cytokine measurements at concentrations down to 5–20 pg/mL from a 1 µL serum sample. Using the nanoplasmonic biosensor microarray device, we demonstrated the ability to monitor the inflammatory responses of infants following cardiopulmonary bypass (CPB

  10. Prevalence of p24 antigen among a cohort of HIV antibody negative blood donors in Sokoto, North Western Nigeria - the question of safety of blood transfusion in Nigeria

    PubMed Central

    Osaro, Erhabor; Mohammed, Ndakotsu; Zama, Isaac; Yakubu, Abdulrahaman; Dorcas, Ikhuenbor; Festus, Aghedo; Kwaifa, Ibrahim; Sani, Ibrahim

    2014-01-01

    Introduction Blood transfusions remain a substantial source of HIV in SSA particularly among children and pregnant women. Aims and objectives: This aim of this retrospective study was to investigate the prevalence of p24 antigen among HIV antibody seronegative blood donors in Sokoto, North West Nigeria. Methods A total of 15,061 HIV antibody negative blood donors with mean age and age range (29.2 ± 8.18 and 18-50 years) were screened for p24 antigen between January 2010 to July 2013 using the Diapro Diagnostic immunoassay kit for P24 antigen (King Hawk Pharmaceuticals Beijing China). Results The overall prevalence of p24 antigen among the HIV antibody negative donors sample was 5.84%. The yearly prevalence was 9.79, 8.12, 2.7 and 2.84% respectively in 2010, 2011, 2012 and 2013. Of the total number of blood donor tested, 14,968 (99.38%) were males while 93 (0.62%) were females. The prevalence of P24 antigen was significantly higher among male blood donors 873 (5.8%) compared to females 7(0.05%), (p= 0.001). P24 positivity was significantly higher among blood group O blood donors compared to A, B and AB donors (494 (3.29%) compared to 184 (1.89%), 196 (1.30%) and 6 (0.04%)) respectively, p = 0.001). The prevalence of P24 antigen was significantly higher among Rhesus positive blood donors compared to Rhesus negative (807 (5.36%) versus 73 (0.48%), p =0.001). Conclusion Blood transfusion in Nigeria is associated with increased risk of HIV transmission. There is the urgent need to optimize the screening of blood donors in Nigeria by the inclusion of p24 antigen testing into the blood donor screening menu. The Nigerian government urgently need to adopt the WHO blood safety strategies to reduce the risk of transmission of HIV through blood transfusion. PMID:25419301

  11. The Psychosocial and Independent Living Donor Advocate Evaluation and Post-surgery Care of Living Donors.

    PubMed

    Rudow, Dianne LaPointe; Swartz, Kathleen; Phillips, Chelsea; Hollenberger, Jennifer; Smith, Taylor; Steel, Jennifer L

    2015-09-01

    Solid organ transplantation as a treatment for end stage organ failure has been an accepted treatment option for decades. Despite advances in medicine and technology, and increased awareness of organ donation and transplantation, the gap between supply and demand continues to widen. Living donation has been an option that has increased the number of transplants despite the continued shortage of deceased organs. In the early 2000s live donor transplantation reached an all-time high in the United States. As a result, a consensus meeting was convened in 2000 to increase the oversight of living donor transplantation. Both the Centers for Medicare and Medicaid Services and the United Network for Organ Sharing developed regulations that transplant programs performing live donor transplantation. These regulations and guidelines involve the education, evaluation, informed consent process and living donor follow-up care. Two areas in which had significant changes included the psychosocial and the independent living donor advocate (ILDA) evaluation. The purpose of this paper was to outline the current regulations and guidelines associated with the psychosocial and ILDA evaluation as well as provide further recommendations for the administration of a high quality evaluation of living donors. The goals and timing of the evaluation and education of donors; qualifications of the health care providers performing the evaluation; components of the evaluation; education provided to donors; documentation of the evaluation; participation in the selection committee meeting; post-decline and post-donation care of donors is described. Caveats including the paired donor exchange programs and non-directed and directed donation are also considered. PMID:26293351

  12. Characteristics, attitudes and personalities of AI donors.

    PubMed

    Nicholas, M K; Tyler, J P

    1983-03-01

    The first 50 men recruited to an artificial insemination by donor (AID) programme have been assessed for their attitudes and characteristics using a basic questionnaire and a standard well evaluated personality inventory. The results have shown that donors can be characterized as stable and moderately extroverted people who come from a wide range of occupations. Their marital and parental status had no particular relationship to their desire to donate and most of them volunteered for altruistic reasons, financial remuneration being a poor inducement. Most subjects lived within the close environs of the Westmead Centre and preferred to donate during normal working hours. The inconvenience of donating appeared to be the most important factor in considering new approaches to recruiting semen donors. PMID:6640474

  13. Donor-recipient matching: myths and realities.

    PubMed

    Briceño, Javier; Ciria, Ruben; de la Mata, Manuel

    2013-04-01

    Liver transplant outcomes keep improving, with refinements of surgical technique, immunosuppression and post-transplant care. However, these excellent results and the limited number of organs available have led to an increasing number of potential recipients with end-stage liver disease worldwide. Deaths on waiting lists have led liver transplant teams maximize every organ offered and used in terms of pre and post-transplant benefit. Donor-recipient (D-R) matching could be defined as the technique to check D-R pairs adequately associated by the presence of the constituents of some patterns from donor and patient variables. D-R matching has been strongly analysed and policies in donor allocation have tried to maximize organ utilization whilst still protecting individual interests. However, D-R matching has been written through trial and error and the development of each new score has been followed by strong discrepancies and controversies. Current allocation systems are based on isolated or combined donor or recipient characteristics. This review intends to analyze current knowledge about D-R matching methods, focusing on three main categories: patient-based policies, donor-based policies and combined donor-recipient systems. All of them lay on three mainstays that support three different concepts of D-R matching: prioritarianism (favouring the worst-off), utilitarianism (maximising total benefit) and social benefit (cost-effectiveness). All of them, with their pros and cons, offer an exciting controversial topic to be discussed. All of them together define D-R matching today, turning into myth what we considered a reality in the past. PMID:23104164

  14. Risks for donors in uterus transplantation.

    PubMed

    Kisu, Iori; Mihara, Makoto; Banno, Kouji; Umene, Kiyoko; Araki, Jun; Hara, Hisako; Suganuma, Nobuhiko; Aoki, Daisuke

    2013-12-01

    Uterus transplantation (UTx) is an alternative to gestational surrogacy and adoption for patients with absolute uterine infertility. Studies have been conducted in animals, and UTx is now within the reach of clinical application in humans. Procedures in humans have been published, but many medical, ethical, and social problems and risks of UTx require discussion prior to widespread clinical application, from the perspectives of donors, recipients, families, and newborns. In this article, we summarize the burdens and risks of UTx, with a focus on donors who provide the uterus. PMID:23793471

  15. Seroepidemiology of Toxoplasma gondii Infection among Healthy Blood Donors in Taiwan

    PubMed Central

    Chiang, Ting-Yi; Hsieh, Hwei-Ho; Kuo, Ming-Chu; Chiu, Kai-Tse; Lin, Wei-Chen; Fan, Chia-Kwung; Fang, Chi-Tai; Ji, Dar-Der

    2012-01-01

    Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3–6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5–19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2–3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1–2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6–3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan. PMID:23133557

  16. A multidisciplinary program to educate and advocate for living donors.

    PubMed

    Sites, Anita K; Freeman, Jason R; Harper, Michael R; Waters, David B; Pruett, Timothy L

    2008-12-01

    Education is critical in decision making and the informed consent process in prospective living donors. Little has been written about how and what living donors should be taught. This article describes a multidisciplinary program for living donor education at the University of Virginia. The goals of the program are to impart information needed for prospective donors to make an informed decision and to independently evaluate donors' medical and psychosocial suitability. A partnership between the transplant department and an independent donor advocacy team establishes an environment conducive to education. By embracing independence, transparency, partnership, and advocacy, our program permits bidirectional education. This partnership facilitates unbiased understanding and appreciation of this education and considers each individual's unique circumstances when making informed decisions. Likewise, prospective donors educate the team about their circumstances, which helps the team safeguard the prospective donor and may enhance the safety of prospective donors and the perceived integrity of living organ donation. PMID:19186581

  17. A commercial rapid optical immunoassay detects Streptococcus agalactiae from aquatic cultures and clinical specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The BioStar STREPT B Optical ImmunoAssay (OIA) (BioStar® OIA® Strep B Assay Kit; Biostar Incorporation; Louisville, CO, USA) was used to identify 32 known group B streptococcus (GBS) isolates of fish, dolphin, bovine, and human origin. Thirteen non-GBS isolates from fish and other animals were test...

  18. Competitive immunoassays for simultaneous detection of metabolites and proteins using micromosaic patterning.

    PubMed

    Murphy, Brian M; He, Xinya; Dandy, David; Henry, Charles S

    2008-01-15

    New high-throughput immunoassay methods for rapid point-of-care diagnostic applications represent an unmet need and current focus of numerous innovative methods. We report a new micromosaic competitive immunoassay developed for the analysis of the thyroid hormone thyroxine (T4), inflammation biomarker C-reactive protein (CRP), and the oxidative damage marker 3-nitrotyrosine (BSA-3NT) on a silicon nitride substrate. To demonstrate the versatility of the method, both direct and indirect format competitive immunoassays were developed and could be applied simultaneously for single samples. Signals from standard solutions were fit to a logistic equation, allowing simultaneous detection of T4 (7.7-257.2 nM), CRP (0.3-4.2 microg/mL), and BSA-3NT (0.03-22.3 microg/mL). Total assay time including sample introduction, washing, and fluorescence measurement was less than 45 min. Dissociation constants for affinity pairs in the system have been estimated using regression. This proof-of-concept experiment shows that both small and macromolecular biomarkers can be quantified from a single sample using the method and suggests that groups of clinically related analytes may be analyzed by competitive micromosaic immunoassay techniques. PMID:18092765

  19. The measurement of triclosan in water using a magnetic particle enzyme immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sensitive magnetic particle-based immunoassay to determine triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) in drinking water and wastewater was developed. Rabbit antiserum was produced by immunizing the rabbit with 6-(5-chloro-2-(2,4-dichlorophenoxy)phenoxy)hexanoic acid-keyhole limpet hemocya...

  20. Production of anti-idiotype antibodies for deoxynivalenol and their evaluation with three immunoassay platforms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays for deoxynivalenol (DON) that involve the competition for binding to DON-specific antibodies have been widely developed. In such assays, the responses of samples are generally compared to calibration curves generated by using DON in competition with labeled reagents such as enzymatic or...

  1. Development of a Nanoparticle-Labeled Microfluidic Immunoassay for Detection of Pathogenic Microorganisms

    PubMed Central

    Lin, Frank Y. H.; Sabri, Mahdi; Alirezaie, Javad; Li, Dongqing; Sherman, Philip M.

    2005-01-01

    The light-scattering properties of submicroscopic metal particles ranging from 40 to 120 nm in diameter have recently been investigated. These particles scatter incident white light to generate monochromatic light, which can be seen either by the naked eye or by dark-field microscopy. The nanoparticles are well suited for detection in microchannel-based immunoassays. The goal of the present study was to detect Helicobacter pylori- and Escherichia coli O157:H7-specific antigens with biotinylated polyclonal antibodies. Gold particles (diameter, 80 nm) functionalized with a secondary antibiotin antibody were then used as the readout. A dark-field stereomicroscope was used for particle visualization in poly(dimethylsiloxane) microchannels. A colorimetric quantification scheme was developed for the detection of the visual color changes resulting from immune reactions in the microchannels. The microchannel immunoassays reliably detected H. pylori and E. coli O157:H7 antigens in quantities on the order of 10 ng, which provides a sensitivity of detection comparable to those of conventional dot blot assays. In addition, the nanoparticles within the microchannels can be stored for at least 8 months without a loss of signal intensity. This strategy provides a means for the detection of nanoparticles in microchannels without the use of sophisticated equipment. In addition, the approach has the potential for use for further miniaturization of immunoassays and can be used for long-term archiving of immunoassays. PMID:15753255

  2. Development of a nanoparticle-labeled microfluidic immunoassay for detection of pathogenic microorganisms.

    PubMed

    Lin, Frank Y H; Sabri, Mahdi; Alirezaie, Javad; Li, Dongqing; Sherman, Philip M

    2005-03-01

    The light-scattering properties of submicroscopic metal particles ranging from 40 to 120 nm in diameter have recently been investigated. These particles scatter incident white light to generate monochromatic light, which can be seen either by the naked eye or by dark-field microscopy. The nanoparticles are well suited for detection in microchannel-based immunoassays. The goal of the present study was to detect Helicobacter pylori- and Escherichia coli O157:H7-specific antigens with biotinylated polyclonal antibodies. Gold particles (diameter, 80 nm) functionalized with a secondary antibiotin antibody were then used as the readout. A dark-field stereomicroscope was used for particle visualization in poly(dimethylsiloxane) microchannels. A colorimetric quantification scheme was developed for the detection of the visual color changes resulting from immune reactions in the microchannels. The microchannel immunoassays reliably detected H. pylori and E. coli O157:H7 antigens in quantities on the order of 10 ng, which provides a sensitivity of detection comparable to those of conventional dot blot assays. In addition, the nanoparticles within the microchannels can be stored for at least 8 months without a loss of signal intensity. This strategy provides a means for the detection of nanoparticles in microchannels without the use of sophisticated equipment. In addition, the approach has the potential for use for further miniaturization of immunoassays and can be used for long-term archiving of immunoassays. PMID:15753255

  3. Competitive chemiluminescent anzyme immunoassay for vitamin B12 analysis in human milk.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent discoveries of matrix interferences by haptocorrin (HC) in human milk and serum show that past analyses of vitamin B12 in samples with high HC content might have been inaccurate (Lildballe et al., 2009; Carmel & Agrawal, 2012). We evaluated two competitive enzyme-binding immunoassays for seru...

  4. Visible paper chip immunoassay for rapid determination of bacteria in water distribution system.

    PubMed

    Ma, Sai; Tang, Yanyan; Liu, Jingqing; Wu, Jianmin

    2014-03-01

    Paper chips for immunoassay were patterned by screen printing of polydimethylsiloxane (PDMS) or wax pencil drawing. The methods for paper chip patterning are cheap, convenient, rapid and suitable for most laboratories. The whole time for patterning a paper chip is no more than 10 min. Visible immunoassay for the detection of bacteria (Escherichia coli ) has been realized using the paper chip, on which the antibody for capturing E. Coli was immobilized on the detection zones of the paper chip, while the detection antibody was labeled with gold nanoparticles (AuNPs) as a signal reporter. After an immunological reaction, the AuNPs bound on the paper chip can effectively catalyse the reduction of silver ions during the silver enhancing step, generating a visible result that can be read by naked eyes. The quantitative results can be acquired by scanning the silver stained paper chip with a commercial scanner/or digital camera. The density of E. coli in water samples can be measured after calibrating the gray value of silver stained spots with the logarithmic number of bacteria. The time and reagents consumed on the paper chip immunoassay is much smaller than those of conventional ELISA, while the sensitivity of the paper chip immunoassay is comparable to conventional ELISA. The technology proposed in this work displays a great potential in the in-situ analysis when daily monitoring of water quality are required. PMID:24468352

  5. Highly sensitive immunoassay based on immunogold-silver amplification and inductively coupled plasma mass spectrometric detection.

    PubMed

    Liu, Rui; Liu, Xing; Tang, Yurong; Wu, Li; Hou, Xiandeng; Lv, Yi

    2011-03-15

    In this work, we demonstrated a highly sensitive inductively coupled plasma mass spectrometric (ICPMS) method for the determination of human carcinoembryonic antigen (CEA), which combined the inherent high sensitivity of elemental mass spectrometric measurement with the signal amplification of catalytic silver deposition on immunogold tags. The silver amplification procedure was easy to handle and required cheap reagents, and the sensitivity was greatly enhanced to 60-fold after a 15 min silver amplification procedure. The experimental conditions, including detection of gold and silver by ICPMS, immunoassay parameters, silver amplification parameters, analytical performance, and clinical serum samples analysis, were investigated. The ICPMS Ag signal intensity depends linearly on the logarithm of the concentration of human CEA over the range of 0.07-1000 ng mL(-1) with a limit of detection (LOD, 3σ) of 0.03 ng mL(-1) (i.e., 0.15 pM). The LOD of the proposed method is around 2 orders of magnitude lower than that by the widely used enzyme-linked immunosorbent assay (ELISA) and 1 order of magnitude lower than that by clinical routine chemiluminescence immunoassay (CLIA) or time-resolved fluoroimmunoassay (TRFIA) and conventional ICPMS immunoassay. The present strategy was applied to the determination of human CEA in clinical human serum samples, and the results were in good agreement with those obtained by chemiluminescence immunoassay. PMID:21348438

  6. Heparin interferes with the radioenzymatic and homogeneous enzyme immunoassays for aminoglycosides

    SciTech Connect

    Krogstad, D.J.; Granich, G.G.; Murray, P.R.; Pfaller, M.A.; Valdes, R.

    1981-07-01

    Heparin interferes with measurement of aminoglycosides in serum by biological, radioenzymatic, and homogeneous enzyme immunoassay techniques, but not with radioimmunoassay. At concentrations greater than or equal to 10/sup 5/ and greater than or equal to 3 X 10/sup 6/ USP units/L, respectively, it interferes with the radioenzymatic assay by inhibiting the gentamicin 3-acetyltransferase and kanamycin 6'-acetyltransferase enzymes used in the assay. It interferes with the homogeneous enzyme immunoassays for gentamicin and tobramycin (at concentrations greater than or equal to 10/sup 5/ and greater than or equal to10/sup 4/ USP units/L, respectively), but not with the commercially available homogeneous enzyme immunoassays for other drugs. Heparin interference with the homogeneous enzyme immunoassay for aminoglycosides requires both the heparin polyanion and glucose-6-phosphate dehydrogenase bound to a cationic aminoglycoside. This interference can be reproduced with dextran sulfate (but not dextran), and does not occur with free enzyme (glucose-6-phosphate dehydrogenase) alone. Heparin interference with these two assays and at concentrations that may be present in intravenous infusions or in seriously underfilled blood-collection tubes is described. (JMT)

  7. ON-SITE MERCURY ANALYSIS OF SOIL AT HAZARDOUS WASTE SITES BY IMMUNOASSAY AND ASV

    EPA Science Inventory

    Two field methods for Hg, immunoassay and anodic stripping voltammetry (ASV), that can provide onsite results for quick decisions at hazardous waste sites were evaluated. Each method was applied to samples from two Superfund sites that contain high levels of Hg; Sulphur Bank Me...

  8. Application and validation of polybrominated diphenyl ethers immunoassay for environmental and food matrices.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sensitive magnetic particle enzyme-linked immunoassay (ELISA) was developed to analyze polybrominated diphenyl ethers (PBDEs) in water, milk, fish, chicken and soil samples. The assay is rapid and can be used to analyze fifty samples in about one hour after sample cleanup. The assay has a limit ...

  9. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...

  10. Magnetic colorimetric immunoassay for human interleukin-6 based on the oxidase activity of ceria spheres.

    PubMed

    Peng, Juan; Guan, Jufang; Yao, Huiqin; Jin, Xiaoyong

    2016-01-01

    A novel magnetic colorimetric immunoassay strategy was designed for sensitive detection of human interleukin-6 (IL-6) using ceria spheres as labels. Ceria spheres showed excellent oxidase activity, which can directly catalyze the oxidation of substrate o-phenylenediamine (OPD) to a stable yellow product, 2,3-diaminophenazine (oxOPD). The absorbance of oxOPD was recorded to reflect the level of IL-6. The relatively mild conditions made the immunoassay strategy more robust, reliable, and easy. A linear relationship between absorbance intensity and the logarithm of IL-6 concentrations was obtained in the range of 0.0001-10 ng mL(-1) with a detection limit of 0.04 pg mL(-1) (S/N = 3). The colorimetric immunoassay exhibited high sensitivity and specificity for the detection of IL-6. This immunoassay has been successfully applied in the detection of IL-6 in serum samples and can be readily extended toward the on-site monitoring of cancer biomarkers in serum samples. PMID:26416691

  11. Statistical approaches to developing a multiplex immunoassay for determining human exposure to environmental pathogens.

    EPA Science Inventory

    This paper describes the application and method performance parameters of a Luminex xMAP™ bead-based, multiplex immunoassay for measuring specific antibody responses in saliva samples (n=5438) to antigens of six common waterborne pathogens (Campylobacter jejuni, Helicobacter pylo...

  12. Lateral flow immunoassay for the rapid detection of citrus tristeza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A lateral flow methodology was developed using gold nanoparticles for rapid detection of Citrus tristeza virus (CTV). The test strip was based on a sandwich immunoassay and could be accomplished within 10 minutes. A sample was considered negative for CTV when only the control line appeared; whereas,...

  13. A 7-plex microbead-based immunoassay for serotyping Shiga toxin-producing Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serotyping of Shiga toxin-producing Escherichia coli (STEC) has been contingent upon the availability of antisera. Here we describe a 7-plex microbead-based immunoassay to simultaneously serotype seven STEC (i.e., belonging to serogroups O26, O45, O103, O111, O121, O145, and O157) by the Luminex xMA...

  14. IMMUNOASSAY METHOD FOR THE DETERMINATION OF PENTACHLOROPHENOL IN SOIL AND SEDIMENT

    EPA Science Inventory

    The journal article describes the use of a prototype immunoassay method for the determination of pentacholorphenol (PCP) in soil and sediment. PCP was used as a pesticide and wood preservative and is not currently available to the general public. The paper stresses the importan...

  15. A homogeneous immunoassay for cyclic nucleotides based on chemiluminescence energy transfer.

    PubMed Central

    Campbell, A K; Patel, A

    1983-01-01

    A chemiluminescent derivative of cyclic AMP, aminobutylethylisoluminol succinyl cyclic AMP (ABEI-scAMP), was synthesized in order to develop a homogeneous immunoassay based on non-radiative energy transfer. ABEI-scAMP was chemiluminescent (5.1 X 10(18) luminescent counts X mol-1 at pH 13), pure (greater than 95%) stable and immunologically active. A conventional immunoassay was established using ABEI-scAMP and a solid-phase anti-(cyclic AMP) immunoglobulin G which could detect cyclic AMP at least down to 25fmol. A homogeneous immunoassay for cyclic AMP was established by measuring the shift in wavelength from 460 to 525nm which occurred when ABEI-scAMP was bound to fluorescein-labelled anti-(cyclic AMP) immunoglobulin G. The assay was at least as sensitive as the conventional radioimmunoassay using cyclic [3H]AMP and could measure cyclic AMP over the range 1-1000nM. The homogeneous chemiluminescent energy transfer assay was also able to quantify the association and dissociation of antibody-antigen complexes. Chemiluminescence energy transfer occurred between fluorescein-labelled antibodies and several other ABEI-labelled antigens (Mr values 314-150000) including progesterone, cyclic GMP, complement component C9 and immunoglobulin G. The results provide a homogeneous immunoassay capable of measuring free cyclic AMP under conditions likely to exist inside cells. PMID:6316935

  16. Rapid Detection of Nivalenol and Deoxynivalenol in Wheat Using Surface Plasmon Resonance Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface plasmon resonance immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A DON-immobilized sensor chip having high sensitivity and stability was prepared, and an SPR detection procedure was developed. The competitiv...

  17. Interference from endogenous antibodies in automated immunoassays: what laboratorians need to know.

    PubMed

    Ismail, A A A

    2009-08-01

    Full automation of laboratory procedures confers numerous advantages over semi-automated/manual tests because equipment, reagents and the computation of results are offered as an integrated package. Automation has allowed millions of immunoassay tests to be performed with good sensitivity and excellent precision but inaccuracy caused by interference from endogenous immunoglobulins/antibodies remained a problem (irrespective of the immunoassay's format). Interference leading to a falsely high or low result affects a specific sample and may not be obvious despite the strictest laboratory control schemes. Reporting and interpreting such potentially erroneous data remained however the responsibility of the clinical laboratory despite the limited information supplied by their providers. The focus of this review is on highlighting the potential downside of current disjointed and blurred arrangement between the developers/providers of immunoassays, and the laboratorians responsible for providing these data to their clinical colleagues. These limitations can be addressed by drawing attention to the importance of the key fundamentals underpinning these immunologically based analyses which, if carefully considered, could help to formulate pragmatic strategies to reduce errors in immunoassays. In this review, the inherent fallibility of the binding reaction between an antigen and antibody will be reiterated. The difficulties in defining reaction rate kinetics in non-equilibrium automated assays, the potential clinical error rate and the need for minimising analytical error rate of these automated technologies will be highlighted. PMID:19638536

  18. Detection of E. coli O157:H7 by immunomagnetic separation coupled with fluorescence immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional culture-based methods for detection of E. coli O157:H7 in foods and water sources are time-consuming, and results can be ambiguous, requiring further confirmation by biochemical testing and PCR. A rapid immunoassay prior to cultivation to identify presumptive positive sample would save...

  19. Metallic nanocrystallites-incorporated ordered mesoporous carbon as labels for a sensitive simultaneous multianalyte electrochemical immunoassay.

    PubMed

    Fang, Yishan; Huang, Xinjian; Zeng, Qiang; Wang, Lishi

    2015-11-15

    This work reports on a facile, novel multianalyte electrochemical immunoassay for simultaneous detection of a-fetoprotein (AFP) and human epidermal growth factor receptor type-2 (HER-2) using metal-containing nanomaterials confined in the ordered mesoporous carbon matrix (OMC-M) as labels. Well-dispersed uniform metallic nanocrystallites incorporated OMC materials were fabricated through a simple, economical, and green preparative strategy toward phenolic resol as a carbon source and metal nitrate as metal sources. The large amount of metallic nanocrystallites loading on the OMC nanomaterials, greatly amplified the detection signals, and the good biocompatibility of carbon nanotubes-chitosan retained excellent stability for the sandwich-type immunoassay. Under optimal experimental conditions, the proposed immunoassay exhibited high sensitivity and selectivity for the detection of analytes, providing a better linear response range from 0.001 to 150 ng/mL for AFP and for HER-2, with a lower limit of detectionof 0.6p g/mL and 0.35 pg/mL (S/N=3), respectively. The immunosensor exhibited convenience, low cost, rapidity, good specificity, acceptable stability and reproducibility. Moreover, satisfactory results were obtained for the determination of AFP and HER-2 in real human serum samples, indicating that the developed immunoassay has the potential to find application in clinical detection of AFP and HER-2 and other tumor markers as an alternative approach. PMID:26046316

  20. Development and application of recombinant antibody-based immunoassays to tetraconazole residue analysis in fruit juices.

    PubMed

    Plana, Emma; Moreno, Maria-José; Montoya, Ángel; Manclús, Juan J

    2014-01-15

    Tetraconazole is currently used as a fungicide in fruit and vegetables. The aim of this work was the development of immunochemical techniques based on recombinant antibodies for the screening of tetraconazole residues in fruit juices. Recombinant antibodies were produced from a hybridoma cell line secreting a monoclonal antibody specific for tetraconazole and from lymphocytes of mice hyperimmunised with tetraconazole haptens conjugated to bovine serum albumin. From these antibodies, enzyme-linked immunosorbent assays in the conjugate-coated format were developed, which were able to detect tetraconazole standards down to 1ng/mL. From recovery studies with spiked samples, these immunoassays determined tetraconazole in orange and apple juices with acceptable reproducibility (coefficients of variation below 25%) and recoveries (ranging from 78% to 145%) for a screening technique. The analytical performance of RAb-based immunoassays was fairly similar to that of the MAb-based immunoassays. Due to their simplicity and high sample throughput, the developed recombinant-based immunoassays can be valuable analytical tools for the screening of tetraconazole residues in fruit juices at regulatory levels. PMID:24054232

  1. Individually addressable electrode array for multianalyte electrochemiluminescent immunoassay based on a sequential triggering strategy.

    PubMed

    Wang, Lin; Wei, Wei; Han, Jing; Fu, Zhifeng

    2012-02-01

    Multianalyte immunoassay in a single run is often necessary to monitor or quantitate several components in a complex sample matrix for various purposes. In this paper we present a novel, individually addressable electrode array for sequential electrochemiluminescent (ECL) immunoassay using a non-array detector. An immunosensor array was fabricated by site-selectively immobilizing multiple antigens on different electrodes. With a competitive immunoassay format, the amounts of the bound Ru(bpy)(3)(2+) derivative labeled antibodies decreased with the increase of the antigens in the sample, and the ECL signals from different immunosensors were collected in turn by a photomultiplier with the aid of a home-made single-pore-three-throw switch. Using human IgG and rat IgG as model analytes, this multianalyte immunoassay showed detection limits down to 8.9 and 7.2 ng mL(-1) for them, respectively. The results for real sample analysis demonstrated that this strategy can provide a simple, sensitive, low-cost and high-throughput ECL immunosensor array for clinical diagnosis. PMID:22159267

  2. Automated digital microfluidic platform for magnetic-particle-based immunoassays with optimization by design of experiments.

    PubMed

    Choi, Kihwan; Ng, Alphonsus H C; Fobel, Ryan; Chang-Yen, David A; Yarnell, Lyle E; Pearson, Elroy L; Oleksak, Carl M; Fischer, Andrew T; Luoma, Robert P; Robinson, John M; Audet, Julie; Wheeler, Aaron R

    2013-10-15

    We introduce an automated digital microfluidic (DMF) platform capable of performing immunoassays from sample to analysis with minimal manual intervention. This platform features (a) a 90 Pogo pin interface for digital microfluidic control, (b) an integrated (and motorized) photomultiplier tube for chemiluminescent detection, and (c) a magnetic lens assembly which focuses magnetic fields into a narrow region on the surface of the DMF device, facilitating up to eight simultaneous digital microfluidic magnetic separations. The new platform was used to implement a three-level full factorial design of experiments (DOE) optimization for thyroid-stimulating hormone immunoassays, varying (1) the analyte concentration, (2) the sample incubation time, and (3) the sample volume, resulting in an optimized protocol that reduced the detection limit and sample incubation time by up to 5-fold and 2-fold, respectively, relative to those from previous work. To our knowledge, this is the first report of a DOE optimization for immunoassays in a microfluidic system of any format. We propose that this new platform paves the way for a benchtop tool that is useful for implementing immunoassays in near-patient settings, including community hospitals, physicians' offices, and small clinical laboratories. PMID:23978190

  3. IMMUNOASSAY METHODS FOR MEASURING ATRAZINE AND 3,5,6-TRICHLORO-2-PYRIDINOL IN FOODS

    EPA Science Inventory

    This chapter describes the use of enzyme-linked immunosorbent assay (ELISA) methods for the analysis of two potential environmental contaminants in food sample media, atrazine and 3,5,6-trichloro-2-pyridinol (3,5,6-TCP). Two different immunoassay formats are employed: a magnetic...

  4. A double-sandwich ELISA for identification of monoclonal antibodies suitable for sandwich immunoassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sandwich immunoassay (sIA) is an invaluable technique for concentrating, detecting, and quantifying target antigens. The two critical components required are a capture antibody and a detection antibody, each binding a different epitope on the target antigen. The specific antibodies incorporated...

  5. Evaluation of two immunoassay procedures for drug testing in hair samples.

    PubMed

    Musshoff, F; Kirschbaum, K M; Graumann, K; Herzfeld, C; Sachs, H; Madea, B

    2012-02-10

    A preliminary initial enzyme-linked immunosorbent assay (LUCIO-Direct ELISA kit) and a preliminary DRI enzyme immunoassay were evaluated for drug detection in head hair with respect to lowered cutoff values recommended in Germany for the control of abstinence in cases of re-granting of drivers' licences. Following drug classes were included: cannabinoids, opiates, cocaine like substances, amphetamine, methamphetamine (and methylenedioxyamphetamines), methadone, and benzodiazepines. 759 analyses were performed using LUCIO-Direct ELISA kits and 936 analyses using DRI enzyme immunoassay tests. Sample size for each drug group and immunoassay test reached from 74 to 178. The LUCIO-Direct ELISA kit revealed a sensitivity of 91% for amphetamine up to 98% for methadone (methamphetamine 92%, cocaine 94%, opiates 94%, benzodiazepines 96%) and values of specificity of 72% for methadone up to 89% for amphetamine and benzodiazepines. The test was not useful for a preliminary screening for tetrahydrocannabinol (sensitivity of 65%) in consideration of a suggested cutoff of 0.02 ng/mg. The DRI enzyme immunoassay test was only useful for morphine and cocaine testing at low recommended new cutoff values (0.1 ng/mg) revealing sensitivities of 94% and 99%, respectively. PMID:21601388

  6. Determination of deoxynivalenol in wheat bran and whole-wheat flour by fluorescence polarization immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds p...

  7. Fluorescence polarization immunoassay using IgY antibodies for detection of valnemulin in swine tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoglobulin Y (IgY) is derived from egg yolk and has been identified as a cheap and high-yield immunoreagent. The application of IgY in immunoassay for the detection of chemical contaminants in food samples has rarely been reported. In this work, we describe a rapid and sensitive fluorescence p...

  8. Fluorescence polarization immunoassays for rapid, accurate and sensitive determination of mycotoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fluorescence polarization immunoassay (FPIA) is a type of homogeneous assay. For low molecular weight antigens, such as mycotoxins, it is based on the competition between an unlabeled antigen and its fluorescent-labeled derivative (tracer) for an antigen-specific antibody. The antigen content is det...

  9. Development and optimization of a fluorescence polarization immunoassay for orbifloxacin in milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A homogeneous microplate-based fluorescence polarization immunoassay (FPIA) for determination of orbifloxacin (ORB) in milk was developed and optimized. A monoclonal antibody of ORB was prepared, and six fluorescent tracers were synthesized from ORB and lomefloxacin (LOM) using three derivatives of...

  10. ENZYME-LINKED IMMUNOASSAYS FOR THE DETECTION OF MICROBIAL ANTIGENS AND THEIR ANTIBODIES

    EPA Science Inventory

    The advantages of enzyme-immunoassay (EIA) over radioactive assay techniques are mainly convenience in use, in that the labelled immunoreagents are stable for long periods, and the precautions and disposal procedures required for radioisotopes are unnecessary. In addition, the us...

  11. 2509 living donor nephrectomies, morbidity and mortality, including the UK introduction of laparoscopic donor surgery.

    PubMed

    Hadjianastassiou, V G; Johnson, R J; Rudge, C J; Mamode, N

    2007-11-01

    The worldwide expansion of laparoscopic, at the expense of open, donor nephrectomy (DN) has been driven on the basis of faster convalescence for the donor. However, concerns have been expressed over the safety of the laparoscopic procedure. The UK Transplant National Registry collecting mandatory information on all living kidney donations in the country was analyzed for donations between November 2000 (start of living donor follow-up data reporting) to June 2006 to assess the safety of living DN, after the recent introduction of the laparoscopic procedure in the United Kingdom. Twenty-four transplant units reported data on 2509 donors (601 laparoscopic, 1800 open and 108 [4.3%] unspecified); 46.5% male; mean donor age: 46 years. There was one death 3 months postdischarge and a further five deaths beyond 1 year postdischarge. The mean length of stay was 1.5 days less for the laparoscopic procedure (p < 0.001). The risk of major morbidity for all donors was 4.9% (laparoscopic = 4.5%, open = 5.1%, p = 0.549). The overall rate of any morbidity was 14.3% (laparoscopic = 10.3%, open = 15.7%, p = 0.001). Living donation has remained a safe procedure in the UK during the learning curve of introduction of the laparoscopic procedure. The latter offers measurable advantages to the donor in terms of reduced length of stay and morbidity. PMID:17868058

  12. When 'sperm' becomes 'donor': transitions in parents' views of the sperm donor.

    PubMed

    Indekeu, Astrid; D'Hooghe, Thomas; Daniels, Ken R; Dierickx, Kris; Rober, Peter

    2014-12-01

    Abstract Little is known about recipients' views of their sperm donor. This study aimed to examine the possible transitions or consistencies in donor sperm recipients' (DSRs') view on the sperm donor over time. A longitudinal qualitative study of 19 Belgian heterosexual DSRs was undertaken. Interviews took place with both partners of the couple during pregnancy, at birth and 1.5-2 years after birth, and were analysed using a grounded theory approach. Recipients who intended to disclose exhibited a transition in their awareness of the donor from being of minimal importance to one who was increasingly seen as part of their family narrative. This was partly triggered by the offspring's life, remarks about resemblance and the socio-cultural context. The perceived position of the donor changed for most recipients from a threatening rival to a 'distractor'. This change was supported by the emerging father-child bond and the confidence that stemmed from it. These observations were applicable to those recipients who intended to disclose their donor conception; for those recipients who intended not to disclose, little or no transition was observed. This study describes and analyses the transitions and consistencies in recipients' views of the donor over different stages of the family life-cycle (pregnancy, birth, toddler stage) and could help the fertility clinics tailor their counselling to the specific stages of parenthood. PMID:24851674

  13. Use of the donor specific transfusion protocol in living-unrelated donor-recipient combinations.

    PubMed Central

    Sollinger, H W; Kalayoglu, M; Belzer, F O

    1986-01-01

    The scarcity of suitable cadaver or living-related kidneys remains the major problem in renal transplantation. The use of the donor-specific transfusion protocol (DST) has allowed for the expansion of the donor pool to one- and two-haplotype mismatched living-related donor-recipient combinations. This study deals with the use of DST in living-unrelated donor-recipient combinations (LURD). The following 34 LURD combinations were entered: husband to wife; wife to husband; friend to friend; stepfather; brother-in-law and sister-in-law. Donor-specific sensitization occurred in 21%. Actuarial graft survival at 4 years is 92.6%, and patient survival is 100%. It is concluded that this study indicates that the results with the use of LURDs equal the results with living-related donors and, therefore, it is suggested that the use of LURDs can be considered in situations when a medically and ethically acceptable unrelated donor is available. PMID:3530155

  14. Related hematopoietic cell donor care: is there a role for unrelated donor registries?

    PubMed

    Anthias, C; van Walraven, S M; Sørensen, B S; de Faveri, G N; Fechter, M; Cornish, J; Bacigalupo, A; Müller, C; Boo, M; Shaw, B E

    2015-05-01

    In almost half of allogeneic hematopoietic progenitor cell (HPC) transplants, a related donor (RD) is used, yet a lack of standardized guidelines means that their care is heterogeneous. Changes to regulatory standards aim to improve uniformity, but adherence to these regulations can prove logistically difficult for the transplant centers (TCs) managing RDs. Discussion has ensued around possible alternative models of related donor care and a session at the European Society for Blood and Marrow Transplantation (EBMT) annual meeting in 2013 debated the question of whether a role exists for unrelated donor registries in the management of 'related' donors. In this overview, we discuss the issues raised at this debate and the pros and cons of donor registry involvement in various aspects of RD management. By examining existing models of related donor care that have been adopted by members of the World Marrow Donor Association (WMDA), we look for ways to enhance and homogenize RD care, while also enabling transplant centers to meet standards required for mandatory accreditation. PMID:25730182

  15. ALTERNATIVE DONORS EXTEND TRANSPLANTATION FOR PATIENTS WITH LYMPHOMA WHO LACK AN HLA MATCHED DONOR

    PubMed Central

    Bachanova, Veronika; Burns, Linda J.; Wang, Tao; Carreras, Jeanette; Gale, Robert Peter; Wiernik, Peter H.; Ballen, Karen K.; Wirk, Baldeep; Munker, Reinhold; Rizzieri, David A.; Chen, Yi-Bin; Gibson, John; Akpek, Görgün; Costa, Luciano J.; Kamble, Rammurti T.; Aljurf, Mahmoud D.; Hsu, Jack W.; Cairo, Mitchell S.; Schouten, Harry C.; Bacher, Ulrike; Savani, Bipin N.; Wingard, John R.; Lazarus, Hillard M.; Laport, Ginna G.; Montoto, Silvia; Maloney, David G.; Smith, Sonali M.; Brunstein, Claudio; Saber, Wael

    2015-01-01

    Alternative donor transplantation is increasingly used for high risk lymphoma patients. We analyzed 1593 transplant recipients (2000 to 2010) and compared transplant outcomes in recipients of 8/8 allele human leukocyte antigen (HLA)-A, -B, -C, and DRB1 matched unrelated donors (MUD; n=1176), 7/8 allele HLA-matched unrelated donors (MMUD; n=275) and umbilical cord blood donors (1 or 2 units UCB; n=142). Adjusted 3-year non-relapse mortality of MMUD (44%) was higher as compared to MUD (35%; p=0.004), but similar to UCB recipients (37%; p=0.19), although UCB had lower rates of neutrophil and platelet recovery compared to unrelated donor groups. With a median follow-up of 55 months, 3-year adjusted cumulative incidence of relapse was lower after MMUD compared with MUD (25% vs 33%, p=0.003) but similar between UCB and MUD (30% vs 33%; p=0.48). In multivariate analysis UCB recipients had lower risks of acute and chronic graft versus host disease compared with adult donor groups (UCB vs MUD: HR=0.68, p=0.05; HR=0.35; p<0.001). Adjusted 3-year overall survival was comparable (43% MUD, 37% MMUD and 41% UCB). Data highlight that patients with lymphoma have acceptable survival after alternative donor transplantation. MMUD and UCB can expand the curative potential of allotransplant to patients who lack suitable HLA-matched sibling or MUD. PMID:25402415

  16. Donor Hemodynamics as a Predictor of Outcomes After Kidney Transplantation From Donors After Cardiac Death.

    PubMed

    Allen, M B; Billig, E; Reese, P P; Shults, J; Hasz, R; West, S; Abt, P L

    2016-01-01

    Donation after cardiac death is an important source of transplantable organs, but evidence suggests donor warm ischemia contributes to inferior outcomes. Attempts to predict recipient outcome using donor hemodynamic measurements have not yielded statistically significant results. We evaluated novel measures of donor hemodynamics as predictors of delayed graft function and graft failure in a cohort of 1050 kidneys from 566 donors. Hemodynamics were described using regression line slopes, areas under the curve, and time beyond thresholds for systolic blood pressure, oxygen saturation, and shock index (heart rate divided by systolic blood pressure). A logistic generalized estimation equation model showed that area under the curve for systolic blood pressure was predictive of delayed graft function (above median: odds ratio 1.42, 95% confidence interval [CI] 1.06-1.90). Multivariable Cox regression demonstrated that slope of oxygen saturation during the first 10 minutes after extubation was associated with graft failure (below median: hazard ratio 1.30, 95% CI 1.03-1.64), with 5-year graft survival of 70.0% (95%CI 64.5%-74.8%) for donors above the median versus 61.4% (95%CI 55.5%-66.7%) for those below the median. Among older donors, increased shock index slope was associated with increased hazard of graft failure. Validation of these findings is necessary to determine the utility of characterizing donor warm ischemia to predict recipient outcome. PMID:26361242

  17. Tissue banking: relationship with blood donor and organ donor card status.

    PubMed

    McKenzie, Kenneth D; Fitzpatrick, Patricia E; Sheehan, John D

    2012-01-01

    Understanding the relationships among altruistic health acts may serve to aid therapeutic research advances. In this paper, we report on the links between two such behaviours-donating blood and carrying an organ donor card-and willingness to donate urological tissue to a tissue bank. Reasons for the differential willingness to do so are examined in this paper. A systematic sample of 259 new and returning attendees at a tertiary urology referral clinic in Ireland completed a self-report questionnaire in an outpatient setting. In addition to demographic details, details of known diagnosis of malignancy and family history of cancer; attitudes to tissue donation for research purposes were gauged using a 5-point Likert scale. Both blood donors and organ donor card carriers were more likely to be willing to donate tissue for research purposes. Blood donors were more likely want to know their overall results in comparison to nonblood donors and want their samples to be used for nonprofit research. Our hypothesis that being a blood donor would be a better predictor to donate urological tissue than being an organ donor card carrier borne out by the trends reported above. PMID:22567418

  18. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

    SciTech Connect

    Jeremy Daniel Driskell

    2006-08-09

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

  19. Compliance with donor age recommendations in oocyte donor recruitment advertisements in the USA.

    PubMed

    Alberta, Hillary B; Berry, Roberta M; Levine, Aaron D

    2013-04-01

    IVF using donated oocytes offers benefits to many infertile patients, yet the technique also raises a number of ethical concerns, including worries about potential physical and psychological risks to oocyte donors. In the USA, oversight of oocyte donation consists of a combination of federal and state regulations and self-regulatory guidelines promulgated by the American Society for Reproductive Medicine. This study assesses compliance with one of these self-regulatory guidelines - specifically, ASRM's preferred minimum age for donors of 21. To assess compliance, 539 oocyte donor recruitment advertisements from two recruitment channels (Craigslist and college newspapers) were collected and evaluated. Of these, 61% in the Craigslist dataset and 43% in the college newspaper dataset listed minimum ages between 18 and 20, which is inconsistent with ASRM's preferred minimum age recommendation of 21. Advertisements placed by oocyte donor recruitment agencies were more likely than advertisements placed by clinics to specify minimum ages between 18 and 20. These results indicate that ASRM should evaluate and consider revising its donor age guidelines. IVF using donated human eggs can help many patients who have difficulty having children. However, the technique also raises ethical concerns, including concerns about potential physical and psychological harms to egg donors. In the USA, oversight of egg donation relies on a combination of federal and state regulation and professional self-regulation. Governmental regulations address only limited aspects of egg donation, such as the potential spread of infectious diseases and the reporting of success rates, leaving voluntary guidelines developed by an association of medical professionals to address most issues, including ethical concerns raised by the practice. One of these voluntary guidelines recommends that egg donors should be at least 21 years of age. In this article, we analysed 539 egg donor recruitment advertisements

  20. Validation of a monoclonal enzyme immunoassay for the determination of carbofuran in fruits and vegetables.

    PubMed

    Moreno, M J; Abad, A; Pelegrí, R; Marínez, M J; Sáez, A; Gamón, M; Montoya, A

    2001-04-01

    The N-methylcarbamate pesticide carbofuran is a very important insecticide used worldwide. In the present work, the validation of a monoclonal antibody-based enzyme immunoassay (ELISA) to determine this compound in fruits and vegetables is described. The immunoassay is a competitive heterologous ELISA in the antibody-coated format, with an I(50) value for standards in buffer of 740 ng/L and with a dynamic range between 200 and 3100 ng/L. For recovery studies, peppers, cucumbers, strawberries, tomatoes, potatoes, oranges, and apples were spiked with carbofuran at 10, 50, and 200 ppb. After liquid extraction, analyses were performed by ELISA on extracts purified on solid-phase extraction (SPE) columns and crude, nonpurified extracts. Depending on the crop, mean recoveries in the 43.9--90.7% range were obtained for purified samples and in the 90.1--121.6% range for crude extracts. The carbofuran immunoassay performance was further validated with respect to high-performance liquid chromatography (HPLC) with postcolumn derivatization and fluorescence detection (EPA Method 531.1). Samples were spiked with carbofuran at several concentrations and analyzed as blind samples by ELISA and HPLC after SPE cleanup. The correlation between methods was very good (y = 0.90x + 2.66, r(2)() = 0.958, n = 25), with HPLC being more precise than ELISA (mean coefficients of variation of 4.1 and 11.5%, respectively). The immunoassay was then applied to the analysis of nonpurified extracts of the same samples. Results also compared very well with those obtained by HPLC on purified samples (y = 1.02x + 10.44, r(2)() = 0.933, n = 29). Therefore, the developed immunoassay is a suitable method for the quantitative and reliable determination of carbofuran in fruits and vegetables even without sample cleanup, which saves time and money and considerably increases the sample throughput. PMID:11308315

  1. A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay.

    PubMed

    Huang, Cheng-Yeh; Tsai, Po-Yen; Lee, I-Chin; Hsu, Hsin-Yun; Huang, Hong-Yuan; Fan, Shih-Kang; Yao, Da-Jeng; Liu, Cheng-Hsien; Hsu, Wensyang

    2016-01-01

    Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications. PMID:26858807

  2. Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.

    PubMed

    Alonso, María Cruz; Trapiella-Alfonso, Laura; Fernández, José M Costa; Pereiro, Rosario; Sanz-Medel, Alfredo

    2016-03-15

    A quantitative immunoassay for the determination of immunoglobulin E (IgE) in human serum using gold nanoclusters (AuNCs) as fluorescent label was developed. Water soluble AuNCs were synthesized using lipoic acid and then thoroughly characterized. The obtained AuNCs have a particle size of 2.7 ± 0.1 nm and maximum fluorescence emission at 710 nm. The synthesized AuNCs showed very good stability of the fluorescent signal with light exposure and at neutral and slightly basic media. A covalent bioconjugation of these AuNCs with the desired antibody was carried out by the carbodiimide reaction. After due optimization of such bioconjugation reaction, a molar ratio 1:3 (antibody:AuNCs) was selected. The bioconjugate maintained an intense luminescence emission, slightly red-shifted as compared to the free AuNCs. Two typical immunoassay configurations, competitive and sandwich, were assayed and their performance for IgE determination critically compared. After the different immunoassay steps were accomplished, the fluorescence emission of the bioconjugate was measured. While the sandwich format provided a detection limit (DL) of 10 ng/mL and a linear range between 25 and 565 ng/mL of IgE, the competitive format revealed a DL of 0.2 ng/mL with a linear range between 0.3 and 7.1 ng/mL The applicability of the more sensitive competitive fluorescent immunoassay was assessed by successful analysis of the IgE in human serum and comparison of results with those from a commercial kit. The main advantages of the proposed AuNCs-based fluorimetric method include a low DL and a simple immunoassay protocol involving few reagents. PMID:26547433

  3. Development and validation of a microfluidic immunoassay capable of multiplexing parallel samples in microliter volumes.

    PubMed

    Ghodbane, Mehdi; Stucky, Elizabeth C; Maguire, Tim J; Schloss, Rene S; Shreiber, David I; Zahn, Jeffrey D; Yarmush, Martin L

    2015-08-01

    Immunoassays are widely utilized due to their ability to quantify a vast assortment of biomolecules relevant to biological research and clinical diagnostics. Recently, immunoassay capabilities have been improved by the development of multiplex assays that simultaneously measure multiple analytes in a single sample. However, these assays are hindered by high costs of reagents and relatively large sample requirements. For example, in vitro screening systems currently dedicate individual wells to each time point of interest and this limitation is amplified in screening studies when the investigation of many experimental conditions is necessary; resulting in large volumes for analysis, a correspondingly high cost and a limited temporal experimental design. Microfluidics based immunoassays have been developed in order to overcome these drawbacks. Together, previous studies have demonstrated on-chip assays with either a large dynamic range, high performance sensitivity, and/or the ability to process samples in parallel on a single chip. In this report, we develop a multiplex immunoassay possessing all of these parallel characteristics using commercially available reagents, which allows the analytes of interest to be easily changed. The device presented can measure 6 proteins in 32 samples simultaneously using only 4.2 μL of sample volume. High quality standard curves are generated for all 6 analytes included in the analysis, and spiked samples are quantified throughout the working range of the assay. In addition, we demonstrate a strong correlation (R(2) = 0.8999) between in vitro supernatant measurements using our device and those obtained from a bench-top multiplex immunoassay. Finally, we describe cytokine secretion in an in vitro inflammatory hippocampus culture system, establishing proof-of-concept of the ability to use this platform as an in vitro screening tool. The low-volume, multiplexing abilities of the microdevice described in this report could be broadly

  4. DONOR-ACCEPTOR INTERACTIONS OF NITROGEN*

    PubMed Central

    Kimura, J. E.; Szent-Györgyi, A.

    1969-01-01

    The nitrogen atoms of organic molecules readily enter into donor-acceptor interactions, giving off an electron from their lone pair. Under favorable conditions the acceptor can form free radicals. S and O atoms behave likewise but less intensely. PMID:4306047

  5. Electron Donor Acceptor Interactions. Final Progress Report

    SciTech Connect

    2002-08-16

    The Gordon Research Conference (GRC) on Electron Donor Acceptor Interactions was held at Salve Regina University, Newport, Rhode Island, 8/11-16/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  6. Case 1: chronic infected donor site.

    PubMed

    2016-03-01

    Following a coronary bypass surgery, a vein donor site became infected and failed to heal despite use of antibiotics and a variety of topical treatments. Octenilin Wound Gel not only helped to promote healing, but also increased the patient's ability to tolerate dressing changes. PMID:26949845

  7. Hydrogen-donor coal liquefaction process

    DOEpatents

    Wilson, Jr., Edward L.; Mitchell, Willard N.

    1980-01-01

    Improved liquid yields are obtained during the hydrogen-donor solvent liquefaction of coal and similar carbonaceous solids by maintaining a higher concentration of material having hydrogenation catalytic activity in the downstream section of the liquefaction reactor system than in the upstream section of the system.

  8. Electron shuttling in phosphorus donor qubit systems

    NASA Astrophysics Data System (ADS)

    Jacobson, N. Tobias; Gamble, John King; Nielsen, Erik; Muller, Richard P.; Witzel, Wayne M.; Montano, Ines; Carroll, Malcolm S.

    2014-03-01

    Phosphorus donors in silicon are a promising qubit architecture, due in large part to their long nuclear coherence times and the recent development of atomically precise fabrication methods. Here, we investigate issues related to implementing qubits with phosphorus donors in silicon, employing an effective mass theory that non-phenomenologically takes into account inter-valley coupling. We estimate the significant sources of decoherence and control errors in this system to compute the fidelity of primitive gates and gate timescales. We include the effects of valley repopulation during the process of shuttling an electron between a donor and nearby interface or between neighboring donors, evaluating the control requirements for ensuring adiabaticity with respect to the valley sector. This work was supported in part by the LDRD program at Sandia National Labs, a multi-program laboratory managed and operated by Sandia Corp, a wholly owned subsidiary of Lockheed Martin Corp, for the U.S. DOE NNSA under contract DE-AC04-94AL85000.

  9. Multifunctional reduced graphene oxide trigged chemiluminescence resonance energy transfer: Novel signal amplification strategy for photoelectrochemical immunoassay of squamous cell carcinoma antigen.

    PubMed

    Zhang, Yan; Sun, Guoqiang; Yang, Hongmei; Yu, Jinghua; Yan, Mei; Song, Xianrang

    2016-05-15

    Herein, a photoelectrochemical (PEC) immunoassay is constructed for squamous cell carcinoma antigen (SCCA) detection using zinc oxide nanoflower-bismuth sulfide (Bi2S3) composites as photoactive materials and reduced graphene oxide (rGO) as signal labels. Horseradish peroxidase is used to block sites against nonspecific binding, and then participated in luminol-based chemiluminescence (CL) system. The induced CL emission is acted as an inner light source to excite photoactive materials, simplifying the instrument. A novel signal amplification strategy is stem from rGO because of the rGO acts as an energy acceptor, while luminol serves as a donor to rGO, triggering the CL resonance energy transfer phenomenon between luminol and rGO. Thus, the efficient CL emission to photoactive materials decreases. Furthermore, the signal amplification caused by rGO labeled signal antibodies is related to photogenerated electron-hole pairs: perfect matching of energy levels between rGO and Bi2S3 makes rGO a sink to capture photogenerated electrons from Bi2S3; the increased steric hindrance hinders the electron donor to the surface of Bi2S3 for reaction with the photogenerated holes. On the basis of the novel signal amplification strategy, the proposed immunosensor exhibits excellent analytical performance for PEC detection of SCCA, ranging from 0.8 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.21 pg mL(-1). Meanwhile, the designed signal amplification strategy provides a general format for future development of PEC assays. PMID:26686924

  10. Hepatitis C virus infection in the asymptomatic British blood donor.

    PubMed

    Mutimer, D J; Harrison, R F; O'Donnell, K B; Shaw, J; Martin, B A; Atrah, H; Ala, F A; Skidmore, S; Hubscher, S G; Neuberger, J M

    1995-01-01

    Blood donor screening for hepatitis C virus (HCV) antibodies is now routine. Most blood transfusion services recommend that seropositive donors are referred for further investigation. Southern European studies suggest that many asymptomatic seropositive donors have clinically significant liver disease. Seropositive donors in areas of high prevalence may not, however, be representative of British donors. We have prospectively examined the prevalence and severity of HCV infection in a British volunteer blood donor population. During a 14 month period, only 0.35% (999/287,332) of all donors in the West Midlands were anti-HCV (screening assay) positive. Only 5% (52/999) of these were confirmed true seropositive. Nearly 80% (41/52) of seropositive donors were referred to the Queen Elizabeth Hospital Liver Unit for further investigation. Most underwent complete investigation, including liver biopsy. Forty of forty-one donors had biochemical, histological, or virological evidence of persistent viral infection. Histological changes were generally mild and none was cirrhotic. Covertly infected patients had less severe disease than those with an overt risk factor for HCV exposure. In the British Midlands, the prevalence of blood donor seropositivity is low. In contrast with seropositive Southern European donors, the British donor is more likely to belong to an at-risk group for parenteral exposure and is less likely to have severe histological changes. This study highlights the importance of developing locally relevant guidelines for the counselling and investigation of anti-HCV-positive blood donors. PMID:7493294

  11. Characteristics of Human Turbinate-Derived Mesenchymal Stem Cells Are Not Affected by Allergic Condition of Donor

    PubMed Central

    Hwang, Se Hwan; Cho, Hye Kyung; Park, Sang Hi; Lee, WeonSun; Lee, Hee Jin; Lee, Dong Chang; Park, Sun Hwa; Lim, Mi Hyun; Back, Sang A; Yun, Byeong Gon; Sun, Dong Il

    2015-01-01

    The characteristics of mesenchymal stem cells (MSCs) derived from human turbinates (hTMSCs) have not been investigated in allergic rhinitis. We evaluated the influence of allergic state of the donor on the characteristics, proliferation, and differentiation potential of hTMSCs, compared with hTMSCs derived from non-allergic patients. hTMSCs were isolated from five non-allergic and five allergic patients. The expression of toll-like receptors (TLRs) in hTMSCs was measured by FACS, and cell proliferation was measured using a cell counting kit. Cytokine secretion was analyzed using multiplex immunoassays. The osteogenic, chondrogenic, and adipogenic differentiation potentials of hTMSCs were evaluated by histology and gene expression analysis. In allergic patients, FACS analysis showed that TLR3 and TLR4 were more highly expressed on the surface of hTMSCs than TLR2 and TLR5. The proliferation of hTMSCs was not influenced by the presence of TLR priming. The expression of IL-6, IL-8, IL-12, IP-10, and RANTES was upregulated after the TLR4 priming. The differentiation potential of hTMSCs was not influenced by TLR priming. These characteristics of hTMSCs were similar to those of hTMSCs from non-allergic patients. We conclude that the allergic condition of the donor does not influence TLR expression, proliferation, or immunomodulatory potential of hTMSCs. PMID:26376485

  12. Achieving donor repetition and motivation by block leaders among current blood donors.

    PubMed

    Martín-Santana, Josefa D; Beerli-Palacio, Asunción

    2012-12-01

    This paper presents an explicative model on the recommendation of donating blood made to relatives and friends by current donors. This model establishes satisfaction and intention to return as direct antecedents, and the quality perceived in the donation process and the existence of inhibitors as indirect antecedents. The results show that (1) the perceived quality has a positive influence on satisfaction and intention to return; (2) the intention to donate again depends positively on satisfaction, but negatively on the existence of internal and external inhibitors; and lastly (3) the recommendation to donate depends on donor satisfaction and their intention to return to donate, this being the most influential factor. At the same time, we contrasted how the model does not vary, whether it is a first-time donor or a repeat donor. PMID:22683233

  13. The personality and motivation of semen donors: a comparison with oocyte donors.

    PubMed

    Schover, L R; Rothmann, S A; Collins, R L

    1992-04-01

    Seventeen consecutively recruited candidates for semen donation were evaluated by a psychologist with testing and a structured interview. Most men (71%) were motivated by financial compensation. Only 29% would donate semen if records were open to potential offspring. Fifty-nine per cent of the men were rated as excellent candidates from a psychological perspective and 35% were rated as acceptable with slight reservations. One was excluded as a donor. Psychological testing revealed mildly abnormal subscale scores for 35% of donors. Forty-seven per cent had histories of minor depressive or anxiety episodes and 35% had had periods of heavy alcohol use. Compared to oocyte donors at the same institution, the men were less altruistic, more affluent, and more likely to have abused alcohol. Women had more traumatic family and reproductive histories. Psychological evaluation can be a valuable tool in gamete donor selection. PMID:1522206

  14. Donor liver dysfunction: application of a new scoring system to identify the marginal donor.

    PubMed

    Ferraz-Neto, B H; Zurstrassen, M P V C; Hidalgo, R; Fonseca, L E P; Motta, T D B; Pandullo, F L; Rezende, M B; Meira-Filho, S P; Sá, J R; Afonso, R C

    2007-10-01

    Livers from marginal donors are increasingly used for transplantation due to the shortage of donor organs. The definition of a marginal donor remains unclear; prediction of organ function is a challenge. In the literature the use of steatotic livers has been associated with poor liver function or even primary dysfunction of the allograft. Tekin et al created a scoring system that classifies a donor as marginal or nonmarginal, using a mathematical model based on donor age and steatosis degree. The aims of this study were to apply the Tekin method to identify marginal and nonmarginal donors and evaluate the influence of the cold ischemia time (CIT) on allograft evolution. We retrospectively reviewed deceased donor liver transplantations performed from October 1995 to March 2006, namely, 177 adult liver transplantations in 163 patients. Fifty-five were excluded due to retransplantation (14) or insufficient data (41). Donor age and macrovesicular steatosis were evaluated according to the mathematical formula proposed by Tekin et al, classifying the donors as marginal versus nonmarginal. The authors also analyzed the CIT, 3-month mortality, and development of primary nonfunction or primary dysfunction. The median donor age was 38.9 years (range, 6-71). The postreperfusion biopsy specimen showed moderate to intense steatosis (>30%) in 14.75% of specimens, with no steatosis or mild steatosis in 85.25%. Sixty-one grafts (50%) developed primary graft dysfunction (PGD): 10 grafts, with primary nonfunction (PNF); and 51 with initial poor function (IPF). Using the criteria provided by Tekin et al, we obtained 41 marginal and 81 nonmarginal allografts. The marginal group showed 61.9% PGD, compared with 59.2% of PGD by the nonmarginal group. The CIT was greater than 12 hours in 5 marginal group transplants and 4 PGD cases (80%). Of the nonmarginal allografts, the CIT was greater than 12 hours in 29.6%, with 75% PGD. The 3-month graft survival rate was 80% in the marginal group

  15. Molecular assembly of amino acid interlinked, topologically symmetric, π-complementary donor-acceptor-donor triads.

    PubMed

    Avinash, M B; Sandeepa, K V; Govindaraju, T

    2013-01-01

    Amino acid interlinked pyrene and naphthalenediimide (NDI) based novel donor-acceptor-donor (D-A-D) triads are designed to exploit their topological symmetry and complementary π-character for facile charge-transfer complexation. Consequently, free-floating high-aspect-ratio supercoiled nanofibres and hierarchical helical bundles of triads are realized by modulating the chemical functionality of interlinking amino acids. PMID:23946856

  16. Donor-Specific HLA Antibodies in Living Versus Deceased Donor Liver Transplant Recipients.

    PubMed

    Levitsky, J; Kaneku, H; Jie, C; Walsh, R C; Abecassis, M; Tambur, A R

    2016-08-01

    With less ischemia, improved donor selection and controlled procedures, living donor liver transplantation (LDLT) might lead to less HLA donor-specific antibody (DSA) formation or fewer adverse outcomes than deceased donor liver transplantation (DDLT). Using the multicenter A2ALL (Adult-to-Adult Living Donor Liver Transplantation Cohort Study) biorepository, we compared the incidence and outcomes of preformed and de novo DSAs between LDLT and DDLT. In total, 129 LDLT and 66 DDLT recipients were identified as having serial samples. The prevalence of preformed and de novo DSAs was not different between DDLT and LDLT recipients (p = 0.93). There was no association between patient survival and the timing (preformed vs. de novo), class (I vs. II) and relative levels of DSA between the groups; however, preformed DSA was associated with higher graft failure only in DDLT recipients (p = 0.01). De novo DSA was associated with graft failure regardless of liver transplant type (p = 0.005) but with rejection only in DDLT (p = 0.0001). On multivariate analysis, DSA was an independent risk factor for graft failure regardless of liver transplant type (p = 0.017, preformed; p = 0.002, de novo). In conclusion, although similar in prevalence, DSA may have more impact in DDLT than LDLT recipients. Although our findings need further validation, future research should more robustly test the effect of donor type and strategies to mitigate the impact of DSA. PMID:26896194

  17. Donor biopsy in living donor liver transplantation: is it still relevant in a developing country?

    PubMed

    Dorwal, P; Gautam, D; Sharma, D; Singh, D R; Raina, V

    2015-04-01

    Liver transplantation is an important modality of treatment for end-stage liver disease. Liver biopsy evaluation has been an important aspect of the donor evaluation protocol. With the advent of newer modalities of donor evaluation such as high resolution CT scan, fibroscan and NMR spectroscopy, the relevance of the liver biopsy appears to be diminishing. We investigated the usefulness of donor liver biopsy evaluation in patients who had been cleared by radiological investigations. We evaluated 184 donor liver biopsies performed over a one-year period and found that 18% showed >5% steatosis and around 40% showed portal inflammation, which was, however, minimal to mild. Fibrosis was detected in 10 cases (5.4%), 7 being in stage 1 and 3 in stage 2. Donors with these findings were not considered for transplantation. We conclude that the liver biopsy still continues to be relevant especially in a developing country and does add additional information to the diagnostic work-up of a liver donor. PMID:25890612

  18. Investigation of Antigen-Antibody Interactions of Sulfonamides with a Monoclonal Antibody in a Fluorescence Polarization Immunoassay Using 3D-QSAR Models

    PubMed Central

    Wang, Zhanhui; Kai, Zhenpeng; Beier, Ross C.; Shen, Jianzhong; Yang, Xinling

    2012-01-01

    A three-dimensional quantitative structure-activity relationship (3D-QSAR) model of sulfonamide analogs binding a monoclonal antibody (MAbSMR) produced against sulfamerazine was carried out by Distance Comparison (DISCOtech), comparative molecular field analysis (CoMFA), and comparative molecular similarity indices analysis (CoMSIA). The affinities of the MAbSMR, expressed as Log10IC50, for 17 sulfonamide analogs were determined by competitive fluorescence polarization immunoassay (FPIA). The results demonstrated that the proposed pharmacophore model containing two hydrogen-bond acceptors, two hydrogen-bond donors and two hydrophobic centers characterized the structural features of the sulfonamides necessary for MAbSMR binding. Removal of two outliers from the initial set of 17 sulfonamide analogs improved the predictability of the models. The 3D-QSAR models of 15 sulfonamides based on CoMFA and CoMSIA resulted in q2 cv values of 0.600 and 0.523, and r2 values of 0.995 and 0.994, respectively, which indicates that both methods have significant predictive capability. Connolly surface analysis, which mainly focused on steric force fields, was performed to complement the results from CoMFA and CoMSIA. This novel study combining FPIA with pharmacophore modeling demonstrates that multidisciplinary research is useful for investigating antigen-antibody interactions and also may provide information required for the design of new haptens. PMID:22754368

  19. Easy come, easy go. Retention of blood donors.

    PubMed

    van Dongen, A

    2015-08-01

    Retention of blood donors has benefits over recruitment of new blood donors. Retention is defined as preventing donors from lapsing and eventually becoming inactive. This review paper discusses literature on the importance of efforts to retain donors, specifically new donors, since lapsing is most common before the fifth donation. Studies have found that intention to donate, attitudes towards blood donation and self-efficacy (does one feel capable of donating blood) are predictors of blood donation. Feelings of 'warm glow' predict donation behaviour better than altruism. The existing literature further suggests that first time donors can be retained by paying extra attention to adverse events (vasovagal reactions and fatigue). These events could be reduced by drinking water and muscle tension exercises. Feelings of anxiety (in regular donors) and stress can further prevent donors from returning. Planning donations amongst busy lives can help retention, and suggestions are given on which interventions might be helpful. PMID:26399971

  20. Alternative donor transplant of benign primary hematologic disorders

    PubMed Central

    Tolar, J; Sodani, P; Symons, H

    2015-01-01

    Hematopoietic SCT is currently the only curative therapy for a range of benign inherited and acquired primary hematologic disorders in children, including BM failure syndromes and hemoglobinopathies. The preferred HLA-matched sibling donor is available for only about 25% of such children. However, there has been substantial progress over the last four decades in the use of alternative donors for those without a matched sibling—including HLA-matched unrelated donors, HLA-haploidentical related donors and unrelated-donor umbilical cord blood—so that it is now possible to find a donor for almost every child requiring an allograft. Below, we summarize the relative merits and limitations of the different alternative donors for benign hematologic conditions, first generally, and then in relation to specific disorders, and suggest recommendations for selecting such an alternative donor. PMID:25665040

  1. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet...

  2. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet...

  3. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.12 Suitability of donor. The source blood for Red Blood Cells shall be obtained from a donor who meets the criteria for...

  4. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.12 Suitability of donor. The source blood for Red Blood Cells shall be obtained from a donor who meets the criteria for...

  5. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.12 Suitability of donor. The source blood for Red Blood Cells shall be obtained from a donor who meets the criteria for...

  6. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.12 Suitability of donor. The source blood for Red Blood Cells shall be obtained from a donor who meets the criteria for...

  7. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet...

  8. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet...

  9. Ethical perspectives on living donor organ transplantation in Asia.

    PubMed

    Concejero, Allan M; Chen, Chao-Long

    2009-12-01

    Live donors are a continuing source of organ grafts for solid organ transplantation in Asia. Ethical issues surrounding the development of living donor organ transplantation in Eastern countries are different from those in Western countries. Donor safety is still the paramount concern in any donor operation. Issues on organ trafficking remain societal concerns in low-income nations. Religion, cultural background, economic prerogatives, and timely legislation contribute to the social acceptance and maturation of organ donation. PMID:19938130

  10. Imaging in Lung Transplantation: Surgical Considerations of Donor and Recipient.

    PubMed

    Backhus, Leah M; Mulligan, Michael S; Ha, Richard; Shriki, Jabi E; Mohammed, Tan-Lucien H

    2016-03-01

    Modifications in recipient and donor criteria and innovations in donor management hold promise for increasing rates of lung transplantation, yet availability of donors remains a limiting resource. Imaging is critical in the work-up of donor and recipient including identification of conditions that may portend to poor posttransplant outcomes or necessitate modifications in surgical technique. This article describes the radiologic principles that guide selection of patients and surgical procedures in lung transplantation. PMID:26896228

  11. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  12. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  13. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  14. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  15. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  16. DEMONSTRATION BULLETIN: PCP IMMUNOASSAY TECHNOLOGIES - PENTA RISC BY ENSYS INC., PENTA RAPID BY OHMICRON CORP., ENVIROGARD BY MILLIPORE

    EPA Science Inventory

    The objectives of this demonstration were to test these field screening technologies for accuracy and precision in detecting Pentachlorophenol (PCP) levels in soil and water by comparing their results with those of a confirmatory laboratory. The three immunoassay technologies ...

  17. Risk Factors for Human Immunodeficiency Virus Infection among Brazilian Blood Donors; a Multicenter Case-Control Study Using Audio Computer-Assisted Structured-Interviews

    PubMed Central

    de Almeida-Neto, Cesar; Goncalez, Thelma T.; Birch, Rebecca Jeffries; de Carvalho, Silvia Maia F.; Capuani, Ligia; Leão, Silvana Carneiro; Miranda, Carolina; Rocha, Pedro Capuani; Carneiro-Proietti, Anna Barbara; Johnson, Bryce R.; Wright, David J.; Murphy, Edward L.; Custer, Brian

    2013-01-01

    Background Although risk factors for HIV infection are known, it is important for blood centers to understand local epidemiology and disease transmission patterns. Current risk factors for HIV infection in blood donors in Brazil were assessed. Methods A case-control study was conducted at large public blood centers located in four major cities between April 2009 – March 2011. Cases were persons whose donations were confirmed positive by enzyme immunoassays followed by Western Blot confirmation. Audio computer-assisted structured-interviews (ACASI) were completed by all cases and controls. Multivariable logistic regression was used to estimate adjusted odds ratios (AORs) and associated 95% confidence intervals (CIs). Results There were 341 cases, including 47 with recently-acquired infection, and 791 controls. Disclosed risk factors for both females and males were sex with an HIV-positive person (adjusted odds ratio (AOR) 11.3, 95% CI [4.1, 31.7]) and being an IVDU or sexual partner of an IVDU (AOR 4.65 [1.8, 11.7]). For female blood donors, additional risk factors were having male sex partners who also are MSM (AOR 13.5 [3.1, 59.8]), and having unprotected sex with multiple sexual partners (AOR 5.19 [2.1, 12.9]). The primary risk factor for male blood donors was MSM activity (AOR 21.6 [8.8, 52.9.]). Behaviors associated with recently-acquired HIV were being a MSM or sex partner of MSM (13.82, [4.7, 40.3]), and IVDU (11.47, [3.0, 43.2]). Conclusion Risk factors in blood donors parallel those in the general population in Brazil. Identified risk factors suggest that donor compliance with selection procedures at the participating blood centers is inadequate. PMID:23517235

  18. Donor center formation in hydrogen implanted silicon

    NASA Astrophysics Data System (ADS)

    Neustroev, E. P.; Antonova, I. V.; Stas, V. F.; Popov, V. P.; Obodnikov, V. I.

    1999-10-01

    The shallow donor centers formed beyond the hydrogen projected range in temperature interval of 350-550°C have been studied in the present work. It has been shown that hydrogen implantation enhances thermal donor (TD) formation in the whole crystal (up to 360 μm). Two different mechanisms of enhancement must be distinguished. The first is a hydrogen-related increase in the TD formation rate, which provides a TD profile up to ∼150 μm described by a diffusion coefficient of 5×10 -9 cm 2/s at 450°C. The second mechanism of acceleration is connected to some mobile point defects (vacancy or interstitial type) from the implanted layer with a diffusion coefficient of about 1×10 -7 cm 2/s. The last mechanism is also manifested in the case of oxygen implantation.

  19. Antidiffusive velocities for multipass donor cell advection

    SciTech Connect

    Margolin, L.; Smolarkiewicz, P.K.

    1999-01-01

    Multidimensional positive definite advection transport algorithm (MPDATA) is an iterative process for approximating the advection equation, which uses a donor cell approximation to compensate for the truncation error of the originally specified donor cell scheme. This step may be repeated an arbitrary number of times, leading to successfully more accurate solutions to the advection equation. In this paper, the authors show how to sum the successive approximations analytically to find a single antidiffusive velocity that represents the effects of an arbitrary number of passes. The analysis is first done in one dimension to illustrate the method and then is repeated in two dimensions. The existence of cross terms in the truncation analysis of the two-dimensional equations introduces an extra complication into the calculation. The authors discuss the implementation of the antidiffusive velocities and provide some examples of applications, including a third-order accurate scheme.

  20. Antidiffusive velocities for multipass donor cell advection

    SciTech Connect

    Margolin, L.G. ); Smolarkiewicz, P.K. )

    1989-12-01

    Smolarkiewicz describes an iterative process for approximating the advection equation. Basically, he uses a donor cell approximation to correct for the truncation error of the originally specified donor cell scheme. This step may be repeated an arbitrary number of times leading to successively more accurate solutions to the advection equation. In this report, we show how to sum the successive approximations analytically to find a single antidiffusive velocity that represents the effects of an arbitrary number of passes. The analysis is first done dimension to illustrate the method. The analysis is then repeated in two dimensions. The existence of cross terms in the truncation analysis of the two-dimensional equations introduces an extra complication into the calculation. We discuss the implementation of our new antidiffusive velocities and provide some examples of applications. 6 refs., 5 figs., 4 tabs.

  1. Living donor liver transplantation in Europe

    PubMed Central

    Capobianco, Ivan; Panaro, Fabrizio; Di Francesco, Fabrizio; Troisi, Roberto; Sainz-Barriga, Mauricio; Muiesan, Paolo; Königsrainer, Alfred; Testa, Giuliano

    2016-01-01

    Living donor liver transplantation (LDLT) sparked significant interest in Europe when the first reports of its success from USA and Asia were made public. Many transplant programs initiated LDLT and some of them especially in Germany and Belgium became a point of reference for many patients and important contributors to the advancement of the field. After the initial enthusiasm, most of the European programs stopped performing LDLT and today the overall European activity is concentrated in a few centers and the number of living donor liver transplants is only a single digit fraction of the overall number of liver transplants performed. In this paper we analyse the present European activities and highlight the European contribution to the advancement of the field of LDLT. PMID:27115011

  2. Psychiatric Aspects of Artificial Insemination (Donor)

    PubMed Central

    Watters, W. W.; Sousa-Poza, J.

    1966-01-01

    Artificial insemination (donor) [A.I.D.] in humans is a medical procedure that has been carried out for roughly 50 years. Its legal status has not yet been established; its moral implications are still hotly contested, and its psychological and psychiatric implications are only now coming under scientific scrutiny. The use of this procedure in couples who are psychologically unsuited for it can have unfortunate consequences. The obstetrician should seek the assistance of a dynamically oriented psychiatrist in screening couples who ask for artificial insemination (donor). Parenthood, in line with psychoanalytic ego psychology, is seen as a phase of ego development. The potential for mothering and fathering children is a later stage in growth than the capacity to conceive and sire them. It is the psychiatrist's role to assess the couple's motivation for A.I.D. in the light of the extent to which they have achieved this degree of ego development. PMID:20328602

  3. Living-donor kidney transplantation: a review of the current practices for the live donor.

    PubMed

    Davis, Connie L; Delmonico, Francis L

    2005-07-01

    The first successful living-donor kidney transplant was performed 50 yr ago. Since then, in a relatively brief period of medical history, living kidney transplantation has become the preferred treatment for those with ESRD. Organ replacement from either a live or a deceased donor is preferable to dialysis therapy because transplantation provides a better quality of life and improved survival. The advantages of live versus deceased donor transplantation now are readily apparent as it affords earlier transplantation and the best long-term survival. Live kidney donation has also been fostered by the technical advance of laparoscopic nephrectomy and immunologic maneuvers that can overcome biologic obstacles such as HLA disparity and ABO or cross-match incompatibility. Congressional legislation has provided an important model to remove financial disincentives to being a live donor. Federal employees now are afforded paid leave and coverage for travel expenses. Candidates for renal transplantation are aware of these developments, and they have become less hesitant to ask family members, spouses, or friends to become live kidney donors. Living donation as practiced for the past 50 yr has been safe with minimal immediate and long-term risk for the donor. However, the future experience may not be the same as our society is becoming increasingly obese and developing associated health problems. In this environment, predicting medical futures is less precise than in the past. Even so, isolated abnormalities such as obesity and in some instances hypertension are no longer considered absolute contraindications to donation. These and other medical risks bring additional responsibility in such circumstances to track the unknown consequences of a live-donor nephrectomy. PMID:15930096

  4. Taking a Step Forward in Laparoscopic Donor Nephrectomy: Transvaginal Retrieval of Donor's Kidney.

    PubMed

    Tan, Ying Hao; Lim, Yu Ming Joel; Ng, Ying Woo; Tiong, Ho Yee

    2016-09-01

    Laparoscopic donor nephrectomy has been broadly recognized as the gold standard for kidney procurement used in kidney transplantation where it is not uncommon for donors to experience discomfort and aesthetic dissatisfaction over larger incision site. Natural orifice transluminal endoscopic surgery is a surgical approach that allows scarless intraabdominal operations through natural orifices, such as the vagina. In this case report, we describe the first case of transvaginal retrieval of donor's kidney at the National University Hospital, Singapore. A 51-year-old Malay lady with no significant medical history volunteered to a living-related kidney donor. Perioperative antibiotics were administered. A 12 mm Excel port was placed over the left iliac fossa with camera insertion. Two additional ports were inserted over the left rectus sheath edge and left costal margin under direct vision. An additional 5 mm port at the left loin was placed for lateral retraction. A vaginal probe was then inserted to facilitate posterior colpotomy and transection of the left uterosacral ligament. Pneumoperitoneum was subsequently maintained with a LiNA McCartney(®) Tube. A 15 mm Endocatch(®) bag was inserted for retrieval of the kidney. The left kidney was placed in the Endocatch bag after transection of the hilar vessels where the kidney was retrieved vaginally with ease. Colpotomy was closed vaginally using Vicryl-0 continuous suture. Total blood loss was noted as 50 mL with warm ischemia time being 7 minutes and the entire retrieval taking totally 20 minutes. Postoperative recovery was uneventful and the donor was discharged stable 3 days postoperation. The transplanted kidney retained normal graft function. Colpotomy retrieval for donor nephrectomy presents an innovative method for specimen retrieval with minimal disruption of donor anatomy. Doing away with laparotomy for kidney retrieval has indeed shown a reduction in recovery time, reduced postoperative pain, and

  5. [The protocol for multi organ donor management].

    PubMed

    Kucewicz, Ewa; Wojarski, Jacek; Zegleń, Sławomir; Saucha, Wojciech; Maciejewski, Tomasz; Pacholewicz, Jerzy; Przybylski, Roman; Knapik, Piotr; Zembala, Marian

    2009-01-01

    Identification and preparation of a potential organ donor requires careful and meticulous intensive care, so that the organs may be harvested in the best possible condition for transplantation. The protocol consists of three key elements: (1) monitoring and haemodynamicstabilisation, (2) hormonal therapy, and (3) adequate mechanical ventilation and nosocomial pneumonia prophylaxis. Standard haemodynamic monitoring should consist of a 12 lead EGG, and direct monitoring of arterial and central venous pressures. Pulmonary artery catheterisation is indicated in donors with a left ventricular ejection fraction (LVEF) below 45%. PCWP should be kept at around 12 mm Hg, Cl at greater than 2.4 L m(-2), and SVR between 800 and 1200 dyn s(-1) cm(-5). When a vasopressor is necessary, vasopressin should be used as the drug of choice. If vasopressin is not available, noradrenaline or adrenaline may be used. Haemoglobin concentration should be maintained between 5.5-6.2 mmol L(-1). In a potential heart donor, troponin concentration should be checked daily. Neutral thermal conditions should be maintained using a warm air blower. A brain dead patient cannot maintain adequate pituitary function, therefore hormone replacement therapy with methylprednisolone, thyroxin and desmopressin is indicated. Glucose concentrations should be kept within the normal range, using insulin if necessary. The lung harvesting protocol should be similarto ARDS treatment guidelines (optimal PEEP, low tidal volumes). Lung recruitment manoeuvres, and aggressive prevention and treatment of nosocomial infection are essential. PMID:20201348

  6. Successful Treatment of Chronic Donor Site Pain

    PubMed Central

    Yanow, Jennifer H; Lorenzo, Luigi Di; Worosilo, Sharon C; Pappagallo, Marco

    2015-01-01

    Introduction: This is a case presentation of a 45-year-old male with chronic donor site pain following autologous iliac crest bone harvest successfully treated with superior cluneal nerve blockade. Donor site pain following autologous bone harvest is a common postoperative complication of lumbar fusion procedures that can cause significant morbidity and diminish quality of life, even in the context of an otherwise successful surgery. Dysfunction of the superior cluneal nerves is an etiology of this chronic pain. The patient’s medical history, attempted treatments, and literature were reviewed. Case Presentation: A 45-year-old male with a six year history of severe pain over the right iliac crest following an otherwise successful lumbar laminectomy and fusion underwent two sets of superior cluneal nerve blocks, with sustained relief of more than 80% at seven months follow up. Conclusions: Donor site pain following autologous iliac crest bone harvest is a common surgical complication that is often resistant to conservative treatments such as physical therapy and oral medications. Blockade of the superior cluneal nerves is a safe and technically simple procedure that may result in long-term pain relief, obviating the need to consider more invasive options. PMID:26587399

  7. Low prevalence of HCV, HIV, and HTLV-I/II infection markers in northwestern Greece: results of a 3-year prospective donor study (1995-1997).

    PubMed

    Zervou, E K.; Boumba, D S.; Liaskos, Ch; Georgiadou, S; Tsianos, E V.; Dalekos, G N.

    2003-02-01

    Background: The risk of infection with transfusion-transmitted viruses has been reduced remarkably. A zero-risk blood supply, however, remains a popular goal. A 3-year prospective donor study was conducted in the Epirus region of Greece to determine the prevalence of human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), hepatitis B virus, and hepatitis C virus (HCV). Herein, we report the prevalence of HIV, HTLV, and HCV infection markers in this area. Methodology: Between January 1, 1995 and December 31, 1997, 6696 donors were investigated for the presence of anti-HIV, anti-HTLV, and anti-HCV antibodies using standard enzyme immunoassays (EIA). Every sample with anti-HCV reactivity by third-generation EIA was further investigated using a third-generation recombinant immunoblot assay (RIBA 3.0) and HCV-RNA by a combination of polymerase chain reaction (PCR) and DNA EIA. Results: None of the donors tested positive for anti-HIV or anti-HTLV antibodies. In contrast, anti-HCV was detected in 41 donors (0.61%). Using a RIBA 3.0 test, eight donors tested positive and eight had indeterminate results, while 25 tested negative. Seven of the eight donors with both EIA and RIBA 3.0 reactivity had increased levels of aminotransferases and detectable serum HCV-RNA. The remaining 34 donors had repeatedly normal aminotransferases and three times negative HCV-RNA. Liver biopsy was performed in anti-HCV/HCV-RNA-positive donors (7/41). The lesions were compatible with chronic hepatitis C in all of them. Conclusion: A zero prevalence of HIV and HTLV infection markers was found. Although the number of annual donations in this study was relatively low, the negative data for HIV and HTLV clearly indicate that rates of these infections are low in our region and that infected donors will be seen infrequently. HCV infection in blood donors remains very low in our region and is similar to the data reported in other industrialized countries. In fact, the prevalence of

  8. Smart CuS Nanoparticles as Peroxidase Mimetics for the Design of Novel Label-Free Chemiluminescent Immunoassay.

    PubMed

    Yang, Zhanjun; Cao, Yue; Li, Juan; Lu, Mimi; Jiang, Zhikang; Hu, Xiaoya

    2016-05-18

    In the present work, a novel label-free chemiluminescent (CL) immunoassay method was designed by employing smart CuS nanoparticles (CuSNPs) as peroxidase mimetics. The CuSNPs were synthesized through a simple coprecipitation method, and showed high catalytic activity and stability. This efficient label-free CL immunoassay could be easily achieved through a simple strategy. First, CuSNPs dispersed in chitosan were modified on the epoxy-functionalized glass slide to form a solid CL signal interface. Streptavidin was then used to functionalize CuSNPs to capture the biotinylated antibody, further producing a sensing interface. After online incubation with antigen molecules, the formed antibody-antigen complex on the biosensing substrate could prevent the diffusion channel of CL substrate toward the signal interface, and restrained the mimic enzyme-catalyzed CL reaction, finally resulting in the decrease of CL signals of the assay system. Compared to the label-based CL immunoassay, the proposed label-free assay mode is more simple, cheap and fast. Using a model analyte alpha-fetoprotein, the label-free CL immunoassay method had a linear range of 0.1-60 ng/mL and a low detection limit of 0.07 ng/mL. Moreover, the peroxidase mimetic-based label-free CL immunoassay system showed good specificity, acceptable repeatability, and good accuracy. The study provided a promising strategy for the development of highly efficient label-free CL immunoassay system. PMID:27137349

  9. The Simoa HD-1 Analyzer: A Novel Fully Automated Digital Immunoassay Analyzer with Single-Molecule Sensitivity and Multiplexing.

    PubMed

    Wilson, David H; Rissin, David M; Kan, Cheuk W; Fournier, David R; Piech, Tomasz; Campbell, Todd G; Meyer, Raymond E; Fishburn, Matthew W; Cabrera, Carlos; Patel, Purvish P; Frew, Erica; Chen, Yao; Chang, Lei; Ferrell, Evan P; von Einem, Volker; McGuigan, William; Reinhardt, Marcus; Sayer, Heiko; Vielsack, Claus; Duffy, David C

    2016-08-01

    Disease detection at the molecular level is driving the emerging revolution of early diagnosis and treatment. A challenge facing the field is that protein biomarkers for early diagnosis can be present in very low abundance. The lower limit of detection with conventional immunoassay technology is the upper femtomolar range (10(-13) M). Digital immunoassay technology has improved detection sensitivity three logs, to the attomolar range (10(-16) M). This capability has the potential to open new advances in diagnostics and therapeutics, but such technologies have been relegated to manual procedures that are not well suited for efficient routine use. We describe a new laboratory instrument that provides full automation of single-molecule array (Simoa) technology for digital immunoassays. The instrument is capable of single-molecule sensitivity and multiplexing with short turnaround times and a throughput of 66 samples/h. Singleplex and multiplexed digital immunoassays were developed for 16 proteins of interest in cardiovascular, cancer, infectious disease, neurology, and inflammation research. The average sensitivity improvement of the Simoa immunoassays versus conventional ELISA was >1200-fold, with coefficients of variation of <10%. The potential of digital immunoassays to advance human diagnostics was illustrated in two clinical areas: traumatic brain injury and early detection of infectious disease. PMID:26077162

  10. Deoxynivalenol-mimic nanobody isolated from a naïve phage display nanobody library and its application in immunoassay.

    PubMed

    Qiu, Yu-Lou; He, Qing-Hua; Xu, Yang; Bhunia, Arun K; Tu, Zhui; Chen, Bo; Liu, Yuan-Yuan

    2015-08-01

    In this study, using mycotoxin deoxynivalenol (DON) as a model hapten, we developed a nanobody-based environmental friendly immunoassay for sensitive detection of DON. Two nanobodies (N-28 and N-31) which bind to anti-DON monoclonal antibody (MAb) were isolated from a naive phage display library. These nanobodies are clonable, thermally stable and mycotoxin-free products and can be served as coating antigen mimetics in heterologous immunoassay. The half inhibition concentration (IC50) of the immunoassay developed with N-28 and N-31 was 8.77 ± 0.41 ng mL(-1) and 19.97 ± 0.84 ng mL(-1), respectively, which were 18- and 8-fold more sensitive than the conventional coating antigen (DON-BSA) based immunoassay. In order to better understand the molecular mechanism of antigen mimicry by nanobody, the 3D structure of "nanobody (N-28) - anti-DON MAb" complex was presented and verified by molecular modeling and alanine-scanning mutagenesis. The results showed that hydrogen bond and hydrophobic interaction formed between Thr 102 - Ser 106 of N-28 and CDR H3 residues of anti-DON antibody may contribute to their binding. This novel concept of enhancing sensitivity of immunoassay for DON based on nanobody may provide potential applications in a general method for immunoassay of various food chemical contaminants. PMID:26320803

  11. Nano-immunoassay with improved performance for detection of cancer biomarkers

    SciTech Connect

    Krasnoslobodtsev, Alexey V.; Torres, Maria P.; Kaur, Sukhwinder; Vlassiouk, Ivan V.; Lipert, Robert J.; Jain, Maneesh; Batra, Surinder K.; Lyubchenko, Yuri L.

    2015-01-01

    Nano-immunoassay utilizing surface-enhanced Raman scattering (SERS) effect is a promising analytical technique for the early detection of cancer. In its current standing the assay is capable of discriminating samples of healthy individuals from samples of pancreatic cancer patients. Further improvements in sensitivity and reproducibility will extend practical applications of the SERS-based detection platforms to wider range of problems. In this report, we discuss several strategies designed to improve performance of the SERS-based detection system. We demonstrate that reproducibility of the platform is enhanced by using atomically smooth mica surface as a template for preparation of capture surface in SERS sandwich immunoassay. Furthermore, the assay's stability and sensitivity can be further improved by using either polymer or graphene monolayer as a thin protective layer applied on top of the assay addresses. The protective layer renders the signal to be more stable against photo-induced damage and carbonaceous contamination.

  12. IFSA: a microfluidic chip-platform for frit-based immunoassay protocols

    NASA Astrophysics Data System (ADS)

    Hlawatsch, Nadine; Bangert, Michael; Miethe, Peter; Becker, Holger; Gärtner, Claudia

    2013-03-01

    Point-of-care diagnostics (POC) is one of the key application fields for lab-on-a-chip devices. While in recent years much of the work has concentrated on integrating complex molecular diagnostic assays onto a microfluidic device, there is a need to also put comparatively simple immunoassay-type protocols on a microfluidic platform. In this paper, we present the development of a microfluidic cartridge using an immunofiltration approach. In this method, the sandwich immunoassay takes place in a porous frit on which the antibodies have immobilized. The device is designed to be able to handle three samples in parallel and up to four analytical targets per sample. In order to meet the critical cost targets for the diagnostic market, the microfluidic chip has been designed and manufactured using high-volume manufacturing technologies in mind. Validation experiments show comparable sensitivities in comparison with conventional immunofiltration kits.

  13. Use of immunoassay testing and landfarming to remediate pesticide - contaminated soil at agrichemical businesses

    SciTech Connect

    Frank, J.F.

    1994-12-31

    The recent combination of two new technologies - immunoassay and landfarming - now offers an efficient, effective and economical option in the remediation of pesticide-contaminated soil. Participation in 28 landfarming projects in Illinois - 20 with pesticide-contaminated soil and eight with fuel-contaminated soil - has convinced the author that the combination offers the best method of remediation for most agrichemical sites. The procedures are currently used in Illinois as well as several other states and are being considered in even more. This paper describes the legislative and regulatory background for landfarming; defines immunoassay testing; defines landfarming: (1) contaminated site sampling and analysis; (2) education of participants; (3) selection of cooperator and host farm; (4) soil spreading considerations; a. rates, b. techniques; host site sampling and analysis; and factors affecting cost.

  14. Design and development of a microarray processing station (MPS) for automated miniaturized immunoassays.

    PubMed

    Pla-Roca, Mateu; Altay, Gizem; Giralt, Xavier; Casals, Alícia; Samitier, Josep

    2016-08-01

    Here we describe the design and evaluation of a fluidic device for the automatic processing of microarrays, called microarray processing station or MPS. The microarray processing station once installed on a commercial microarrayer allows automating the washing, and drying steps, which are often performed manually. The substrate where the assay occurs remains on place during the microarray printing, incubation and processing steps, therefore the addressing of nL volumes of the distinct immunoassay reagents such as capture and detection antibodies and samples can be performed on the same coordinate of the substrate with a perfect alignment without requiring any additional mechanical or optical re-alignment methods. This allows the performance of independent immunoassays in a single microarray spot. PMID:27405464

  15. A competitive chemiluminescence enzyme immunoassay for rapid and sensitive determination of enrofloxacin

    NASA Astrophysics Data System (ADS)

    Yu, Fei; Wu, Yongjun; Yu, Songcheng; Zhang, Huili; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B.

    With alkaline phosphatase (ALP)-adamantane (AMPPD) system as the chemiluminescence (CL) detection system, a highly sensitive, specific and simple competitive chemiluminescence enzyme immunoassay (CLEIA) was developed for the measurement of enrofloxacin (ENR). The physicochemical parameters, such as the chemiluminescent assay mediums, the dilution buffer of ENR-McAb, the volume of dilution buffer, the monoclonal antibody concentration, the incubation time, and other relevant variables of the immunoassay have been optimized. Under the optimal conditions, the detection linear range of 350-1000 pg/mL and the detection limit of 0.24 ng/mL were provided by the proposed method. The relative standard deviations were less than 15% for both intra and inter-assay precision. This method has been successfully applied to determine ENR in spiked samples with the recovery of 103%-96%. It showed that CLEIA was a good potential method in the analysis of residues of veterinary drugs after treatment of related diseases.

  16. Nano-immunoassay with improved performance for detection of cancer biomarkers

    DOE PAGESBeta

    Krasnoslobodtsev, Alexey V.; Torres, Maria P.; Kaur, Sukhwinder; Vlassiouk, Ivan V.; Lipert, Robert J.; Jain, Maneesh; Batra, Surinder K.; Lyubchenko, Yuri L.

    2015-01-01

    Nano-immunoassay utilizing surface-enhanced Raman scattering (SERS) effect is a promising analytical technique for the early detection of cancer. In its current standing the assay is capable of discriminating samples of healthy individuals from samples of pancreatic cancer patients. Further improvements in sensitivity and reproducibility will extend practical applications of the SERS-based detection platforms to wider range of problems. In this report, we discuss several strategies designed to improve performance of the SERS-based detection system. We demonstrate that reproducibility of the platform is enhanced by using atomically smooth mica surface as a template for preparation of capture surface in SERS sandwichmore » immunoassay. Furthermore, the assay's stability and sensitivity can be further improved by using either polymer or graphene monolayer as a thin protective layer applied on top of the assay addresses. The protective layer renders the signal to be more stable against photo-induced damage and carbonaceous contamination.« less

  17. Advances in ovarian cancer diagnosis: A journey from immunoassays to immunosensors.

    PubMed

    Sharma, Shikha; Raghav, Ragini; O'Kennedy, Richard; Srivastava, Sudha

    2016-07-01

    This review focuses on the technological advancements, challenges and trends in immunoassay technologies for ovarian cancer diagnosis. Emphasis is placed on the principles of the technologies, their merits and limitations and on the evolution from laboratory-based methods to point-of-care devices. While the current market is predominantly associated with clinical immunoassay kits, over the last decade a major thrust in development of immunosensors is evident due to their potential in point-of-care devices. Technological advancements in immunosensors, extending from labeled to label-free detection, with and without mediators, for enhancing proficiencies and reliability have been dealt with in detail. Aspects of the utilisation of nanomaterials and immobilization strategies for enhancing sensitivity and altering the detection range have also been addressed. Finally, we have discussed some distinct characteristics and limitations associated with the recently commericalised technologies used for quantitation of relevant ovarian cancer markers. PMID:27233124

  18. [The validation of an enzyme immunoassay for the detection of antibodies to bovine leukosis virus].

    PubMed

    Olechnowitz, A F; Miko, A; Koepernik, H; Starick, E; Fröbe, I

    1990-01-01

    Validation of an enzyme immuno-assay for detection of antibodies against bovine leucosis virus is described in this paper. Internal standardisation of the test was done by means of a negative control serum. With absolute extinction of the negative control serum between 100 and 200 mE, a serum sample is rated positive, if its extinction is 1.5 times above the control. The methodological sensitivity of the enzyme immuno-assay described has proved to be four times as high as that of the immunodiffusion test. The results recorded at five diagnostic laboratories suggested a sensitivity of the test of 97.6 percent (92.1 to 100 percent) and a specificity of 98.1 percent (94.4 to 100 percent). The high efficiency of the test can be confirmed by immunoblotting. PMID:2167052

  19. Graphene oxide as nanocarrier for sensitive electrochemical immunoassay of clenbuterol based on labeling amplification strategy.

    PubMed

    Lai, Yanjun; Bai, Jing; Shi, Xinhao; Zeng, Yanbo; Xian, Yuezhong; Hou, Jie; Jin, Litong

    2013-03-30

    A novel electrochemical immunosensor for sensitive detection of clenbuterol (CLB) is fabricated using glucose oxidase (GOD)-functionalized grahene oxide (GO) nanocomposites to label CLB. The immunosensor was constructed by layer-by-layer assembly colloidal prussian blue (PB), multiwalled carbon nanotubes (MWCNTs) and CLB antibodies (Abs) on a glassy carbon electrode (GCE). In this competitive immunoassay system, PB acts as the redox mediator to reduce H2O2 originated from the catalyst cycle of GOD. The high ratio of GOD to GO effectively amplified the signal for this competitive-type immunoassay. Under optimized conditions, the immunosensor shows a wide linear range from 0.5 to 1,000 ng/mL with a low detection limit of 0.25 ng/mL. The dual signal amplification of GOD-functionalized GO nanocomposites as a label is promising to be applied to design other sensitive immunosenseors. PMID:23598209

  20. Microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species in blood.

    PubMed Central

    Fujita, S; Lasker, B A; Lott, T J; Reiss, E; Morrison, C J

    1995-01-01

    We developed a microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species. Nucleotide sequences derived from the internal transcribed spacer (ITS) region of fungal rDNA were used to develop species-specific oligonucleotide probes for Candida albicans, C. tropicalis, C. parapsilosis, and C. krusei. No cross-hybridization was detected with any other fungal, bacterial, or human DNAs tested. In contrast, a C. (Torulopsis) glabrata probe cross-reacted with Saccharomyces cerevisiae DNA but with no other DNAs tested. Genomic DNA purified from C. albicans blastoconidia suspended in blood was amplified by PCR with fungus-specific universal primers ITS3 and ITS4. With the C. albicans-specific probe labeled with digoxigenin, a biotinylated capture probe, and streptavidin-coated microtitration plates, amplified DNA from a few as two C. albicans cells per 0.2 ml of blood could be detected by enzyme immunoassay. PMID:7790469

  1. Two dimensional barcode-inspired automatic analysis for arrayed microfluidic immunoassays

    PubMed Central

    Zhang, Yi; Qiao, Lingbo; Ren, Yunke; Wang, Xuwei; Gao, Ming; Tang, Yunfang; Jeff Xi, Jianzhong; Fu, Tzung-May; Jiang, Xingyu

    2013-01-01

    The usability of many high-throughput lab-on-a-chip devices in point-of-care applications is currently limited by the manual data acquisition and analysis process, which are labor intensive and time consuming. Based on our original design in the biochemical reactions, we proposed here a universal approach to perform automatic, fast, and robust analysis for high-throughput array-based microfluidic immunoassays. Inspired by two-dimensional (2D) barcodes, we incorporated asymmetric function patterns into a microfluidic array. These function patterns provide quantitative information on the characteristic dimensions of the microfluidic array, as well as mark its orientation and origin of coordinates. We used a computer program to perform automatic analysis for a high-throughput antigen/antibody interaction experiment in 10 s, which was more than 500 times faster than conventional manual processing. Our method is broadly applicable to many other microchannel-based immunoassays. PMID:24404030

  2. Semi-automated continuous-flow enzyme immunoassay for antiepileptic drugs in serum.

    PubMed

    Hayashi, S; Kurooka, S; Arisue, K; Kohda, K; Hayashi, C

    1983-10-01

    We have developed a semi-automated method for measuring five kinds of antiepileptic drugs in serum by successfully adapting commercial competitive-binding enzyme immunoassay kits (MARKIT; Dainippon) for use with a continuous-flow analyzer (Technicon AutoAnalyzer II equipped with a dialyzer). The free enzyme-labeled drug is automatically separated by a microfilter from the competitive immunoreaction mixture between labeled and unlabeled drug for anti-drug immunoglobulin coupled to bacterial cell walls. The concentrations of the antiepileptic drugs in serum samples can be determined by automated measurement of enzyme activity of the enzyme-labeled drugs. Results of the semi-automated method correlated well with those obtained by manual enzyme immunoassay, gas-liquid chromatography, and "high-pressure" liquid chromatography. The correlation coefficients were all greater than 0.95, showing the practicality of this method for therapeutic monitoring of antiepileptic drugs. PMID:6352086

  3. Serologic test-systems development: immunoassays for antibiotics. Progress report, May 16, 1980-September 30, 1981

    SciTech Connect

    Brake, R.; Hollstein, U.; Hindman, K.

    1983-04-01

    Progress on development of immunoassays for the antibiotics gentamicin, tetracycline, and tylosin is discussed. The development of the gentamicin assay was completed and the assay was transferred to the Beltsville Laboratories of the US Department of Agriculture (USDA) Food Safety and Quality Service (FSQS). The sensitivity (1 ppB) is 50-fold greater than we have previously reported, and is satisfactory for the current needs. At year's end, work was still in progress on both the tetracycline and tylosin assays. Tetracycline presents a more difficult problem of chemistry than we had anticipated. Immunoassay reagents synthesized by diazonium coupling were only weakly immunoreactive; analysis suggests that this coupling procedure damages the tetracycline structure. Several tetracycline derivatives that offer promising alternative coupling procedures were synthesized. Tylosin was successfully coupled to peroxidase. With this conjugate and antiserum, obtained from R. Mageau of the USDA, some immune-specific binding was demonstrated. Several problems with the tylosin assay remain to be resolved.

  4. Transport through a single donor in p-type silicon

    NASA Astrophysics Data System (ADS)

    Miwa, J. A.; Mol, J. A.; Salfi, J.; Rogge, S.; Simmons, M. Y.

    2013-07-01

    Single phosphorus donors in silicon are promising candidates as qubits in the solid state. Here, we present low temperature scanning probe microscopy and spectroscopy measurements of individual phosphorus dopants deliberately placed in p-type silicon ˜1 nm below the surface. The ability to image individual dopants combined with scanning tunnelling spectroscopy allows us to directly study the transport mechanism through the donor. We show that for a single P donor, transport is dominated by a minority carrier recombination process with the surrounding p-type matrix. The understanding gained will underpin future studies of atomically precise mapping of donor-donor interactions in silicon.

  5. A competitive enzyme immunoassay for the quantitative detection of cocaine from banknotes and latent fingermarks.

    PubMed

    van der Heide, Susan; Garcia Calavia, Paula; Hardwick, Sheila; Hudson, Simon; Wolff, Kim; Russell, David A

    2015-05-01

    A sensitive and versatile competitive enzyme immunoassay (cEIA) has been developed for the quantitative detection of cocaine in complex forensic samples. Polyclonal anti-cocaine antibody was purified from serum and deposited onto microtiter plates. The concentration of the cocaine antibody adsorbed onto the plates, and the dilution of the cocaine-HRP hapten were both studied to achieve an optimised immunoassay. The method was successfully used to quantify cocaine in extracts taken from both paper currency and latent fingermarks. The limit of detection (LOD) of 0.162ngmL(-1) achieved with the assay compares favourably to that of conventional chromatography-mass spectroscopy techniques, with an appropriate sensitivity for the quantification of cocaine at the low concentrations present in some forensic samples. The cEIA was directly compared to LC-MS for the analysis of ten UK banknote samples. The results obtained from both techniques were statistically similar, suggesting that the immunoassay was unaffected by cross-reactivity with potentially interfering compounds. The cEIA was used also for the detection of cocaine in extracts from latent fingermarks. The results obtained were compared to the cocaine concentrations detected in oral fluid sampled from the same individual. Using the cEIA, we have shown, for the first time, that endogeneously excreted cocaine can be detected and quantified from a single latent fingermark. Additionally, it has been shown that the presence of cocaine, at similar concentrations, in more than one latent fingermark from the same individual can be linked with those concentrations found in oral fluid. These results show that detection of drugs in latent fingermarks could directly indicate whether an individual has consumed the drug. The specificity and feasibility of measuring low concentrations of cocaine in complex forensic samples demonstrate the effectiveness and robustness of the assay. The immunoassay presents a simple and cost

  6. Progress in enzyme immunoassays: production of reagents, experimental design, and interpretation*

    PubMed Central

    Kurstak, Edouard

    1985-01-01

    Enzyme immunoassays represent in many cases the preferred procedure for the detection of antigens or corresponding antibodies. However, many of the current procedures are performed suboptimally. This article reviews the available designs, auxiliary recognition systems, production and purification of antibodies, conjugation procedures, solid-phase materials, recording and interpretation of results, and quality control and standardization of procedures to improve the reproducibility of tests. PMID:3910300

  7. Magnetic Electrochemical Immunoassays with Quantum Dot Labels for Detection of Phosphorylated Acetylcholinesterase in Plasma

    SciTech Connect

    Wang, Hua; Wang, Jun; Timchalk, Charles; Lin, Yuehe

    2008-11-01

    A new magnetic electrochemical immunoassay has been developed as a tool for biomonitoring exposures to organophosphate (OP) compounds, e.g., insecticides and chemical nerve agents, by directly detecting organophosphorylated acetylcholinesterase (OP-AChE). This immunoassay uniquely incorporates highly efficient magnetic separation with ultrasensitive square wave voltammetry (SWV) analysis with quantum dots (QDs) as labels. A pair of antibodies was used to achieve the specific recognition of OP-AChE that was prepared with paraoxon as an OP model agent. Antiphosphoserine polyclonal antibodies were anchored on amorphous magnetic particles preferably chosen to capture OP-AChE from the sample matrixes by binding their phosphoserine moieties that were exposed through unfolding the protein adducts. This was validated by electrochemical examinations and enzyme-linked immunosorbent assays. Furthermore, antihuman AChE monoclonal antibodies were labeled with cadmium-source QDs to selectively recognize the captured OP-AChE, as characterized by transmission electron microscopy. The subsequent electrochemical SWV analysis of the cadmium component released by acid from the coupled QDs was conducted on disposable screen-printed electrodes. Experimental results indicated that the SWV-based immunoassays could yield a linear response over a broad concentration range of 0.3-300 ng/mL OP-AChE in human plasma with a detection limit of 0.15 ng/mL. Such a novel electrochemical immunoassay holds great promise as a simple, selective, sensitive, and field-deployable tool for the effective biomonitoring and diagnosis of potential exposures to nerve agents and pesticides.

  8. Development of a prototype lateral flow immunoassay (LFI) for the rapid diagnosis of melioidosis.

    PubMed

    Houghton, Raymond L; Reed, Dana E; Hubbard, Mark A; Dillon, Michael J; Chen, Hongjing; Currie, Bart J; Mayo, Mark; Sarovich, Derek S; Theobald, Vanessa; Limmathurotsakul, Direk; Wongsuvan, Gumphol; Chantratita, Narisara; Peacock, Sharon J; Hoffmaster, Alex R; Duval, Brea; Brett, Paul J; Burtnick, Mary N; Aucoin, David P

    2014-03-01

    Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD) to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS) and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb), an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI); the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (∼0.2 ng/ml). The analytical reactivity (inclusivity) of the AMD LFI was 98.7% (76/77) when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity) testing determined that 97.2% of B. pseudomallei near neighbor species (35/36) were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation. PMID:24651568

  9. A nonenzymatic optical immunoassay strategy for detection of Salmonella infection based on blue silica nanoparticles.

    PubMed

    Sun, Qian; Zhao, Guangying; Dou, Wenchao

    2015-10-22

    A novel nonenzymatic optical immunoassay strategy was for the first time designed and utilized for sensitive detection of antibody to Salmonella pullorum and Salmonella gallinarum (S. pullorum and S. gallinarum) in serum. The optical immunoassay strategy was based on blue silica nanoparticles (Blue-SiNps) and magnetic beads (MB). To construct such an optical immunoassay system, the Blue-SiNPs were first synthesized by inverse microemulsion method, characterized by SEM, Zeta potential and FTIR. Two nanostructures including Blue-SiNPs and MB were both functionalized with antibody against S. pullorum and S. gallinarum (anti-PG) without using enzyme labeled antibody. Anti-PG functionalized blue silica nanoparticles (IgG-Blue-SiNps) were used as signal transduction labels, while anti-PG functionalized magnetic beads (IgG-MB) were selected to separate and enrich the final sandwich immune complexes. In the process of detecting negative serum, a sandwich immunocomplex is formed between the IgG-MB and IgG-Blue-SiNPs. With the separation of the immunocomplex using an external magnetic field, the final plaque displayed bright blue color. While in the detection of infected serum, IgG-MB and anti-PG formed sandwich immunocomplexes, IgG-Blue-SiNPs were unable to bind to the limited sites of the antigen, and a light brown plaque was displayed in the bottom of microplate well. Stable results were obtained with an incubation time of 60 min at room temperature, and different colors corresponding to different results can be directly detected with naked eye. The reaction of IgG-Blue-SiNPs with S. pullorum was inhibited by 1:100 dilution of positive chicken serum. Such a simple immunoassay holds great potential as sensitive, selective and point-of-care (POC) tool for diagnosis of other biological molecules. PMID:26526916

  10. In situ deposition of Prussian blue on mesoporous carbon nanosphere for sensitive electrochemical immunoassay.

    PubMed

    Lai, Guosong; Zhang, Haili; Yu, Aimin; Ju, Huangxian

    2015-12-15

    A Prussian blue (PB) functionalized mesoporous carbon nanosphere (MCN) composite was prepared for loading signal antibody and high-content glucose oxidase (GOD) to obtain a new nanoprobe for sensitive electrochemical immunoassay. The MCN nanocarrier with an average diameter of 180 nm was synthesized by using mesoporous silica nanosphere as a hard template in combination with a hydrothermal carbonization method. This hydrophilic carbon nanomaterial provided an ideal platform for in situ deposition of high-content PB to form the MCN-PB nanocomposite. Based on the step-wise assembly of polyelectrolyte and gold nanoparticles (Au NPs) on the negative-charged nanocomposite, signal antibody and high-content GOD were loaded on this nanocarrier to obtain the nanoprobe. After a sandwich immunoreaction at an Au NPs-modified screen-printed carbon electrode based immunosensor, the nanoprobes were quantitatively captured on the electrode surface to produce sensitive electrochemical response with a PB-mediated GOD catalytic reaction for immunoassay. The high loading of PB and GOD on the nanoprobe greatly amplified the electrochemical signal, leading to the development of a new immunoassay method with high sensitivity. Using human immunoglobulin G as a model analyte, excellent analytical performance including a wide linear range from 0.01 to 100 ng/mL and a low detection limit down to 7.8 pg/mL was obtained. Additionally, the immunosensor showed high specificity, satisfactory stability and repeatability as well as acceptable reliability. The PB-mediated GOD electrochemical system well excluded the conventional interference from the dissolved oxygen. Thus this immunoassay method provides great potentials for practical applications. PMID:26201983

  11. Improvement of immunoassay detection system by using alternating current magnetic susceptibility.

    PubMed

    Kawabata, R; Mizoguchi, T; Kandori, A

    2016-03-01

    A major goal with this research was to develop a low-cost and highly sensitive immunoassay detection system by using alternating current (AC) magnetic susceptibility. We fabricated an improved prototype of our previously developed immunoassay detection system and evaluated its performance. The prototype continuously moved sample containers by using a magnetically shielded brushless motor, which passes between two anisotropic magneto resistance (AMR) sensors. These sensors detected the magnetic signal in the direction where each sample container passed them. We used the differential signal obtained from each AMR sensor's output to improve the signal-to-noise ratio (SNR) of the magnetic signal measurement. Biotin-conjugated polymer beads with avidin-coated magnetic particles were prepared to examine the calibration curve, which represents the relation between AC magnetic susceptibility change and polymer-bead concentration. For the calibration curve measurement, we, respectively, measured the magnetic signal caused by the magnetic particles by using each AMR sensor installed near the upper or lower part in the lateral position of the passing sample containers. As a result, the SNR of the prototype was 4.5 times better than that of our previous system. Moreover, the data obtained from each AMR sensor installed near the upper part in the lateral position of the passing sample containers exhibited an accurate calibration curve that represented good correlation between AC magnetic susceptibility change and polymer-bead concentration. The conclusion drawn from these findings is that our improved immunoassay detection system will enable a low-cost and highly sensitive immunoassay. PMID:27036824

  12. Improvement of immunoassay detection system by using alternating current magnetic susceptibility

    NASA Astrophysics Data System (ADS)

    Kawabata, R.; Mizoguchi, T.; Kandori, A.

    2016-03-01

    A major goal with this research was to develop a low-cost and highly sensitive immunoassay detection system by using alternating current (AC) magnetic susceptibility. We fabricated an improved prototype of our previously developed immunoassay detection system and evaluated its performance. The prototype continuously moved sample containers by using a magnetically shielded brushless motor, which passes between two anisotropic magneto resistance (AMR) sensors. These sensors detected the magnetic signal in the direction where each sample container passed them. We used the differential signal obtained from each AMR sensor's output to improve the signal-to-noise ratio (SNR) of the magnetic signal measurement. Biotin-conjugated polymer beads with avidin-coated magnetic particles were prepared to examine the calibration curve, which represents the relation between AC magnetic susceptibility change and polymer-bead concentration. For the calibration curve measurement, we, respectively, measured the magnetic signal caused by the magnetic particles by using each AMR sensor installed near the upper or lower part in the lateral position of the passing sample containers. As a result, the SNR of the prototype was 4.5 times better than that of our previous system. Moreover, the data obtained from each AMR sensor installed near the upper part in the lateral position of the passing sample containers exhibited an accurate calibration curve that represented good correlation between AC magnetic susceptibility change and polymer-bead concentration. The conclusion drawn from these findings is that our improved immunoassay detection system will enable a low-cost and highly sensitive immunoassay.

  13. Statistical approaches to developing a multiplex immunoassay for determining human exposure to environmental pathogens.

    PubMed

    Augustine, Swinburne A J; Simmons, Kaneatra J; Eason, Tarsha N; Griffin, Shannon M; Curioso, Clarissa L; Wymer, Larry J; Fout, G Shay; Grimm, Ann C; Oshima, Kevin H; Dufour, Al

    2015-10-01

    There are numerous pathogens that can be transmitted through water. Identifying and understanding the routes and magnitude of exposure or infection to these microbial contaminants are critical to assessing and mitigating risk. Conventional approaches of studying immunological responses to exposure or infection such as Enzyme-Linked Immunosorbent Assays (ELISAs) and other monoplex antibody-based immunoassays can be very costly, laborious, and consume large quantities of patient sample. A major limitation of these approaches is that they can only be used to measure one analyte at a time. Multiplex immunoassays provide the ability to study multiple pathogens simultaneously in microliter volumes of samples. However, there are several challenges that must be addressed when developing these multiplex immunoassays such as selection of specific antigens and antibodies, cross-reactivity, calibration, protein-reagent interferences, and the need for rigorous optimization of protein concentrations. In this study, a Design of Experiments (DOE) approach was used to optimize reagent concentrations for coupling selected antigens to Luminex™ xMAP microspheres for use in an indirect capture, multiplex immunoassay to detect human exposure or infection from pathogens that are potentially transmitted through water. Results from Helicobacter pylori, Campylobacter jejuni, Escherichia coli O157:H7, and Salmonella typhimurium singleplexes were used to determine the mean concentrations that would be applied to the multiplex assay. Cut-offs to differentiate between exposed and non-exposed individuals were determined using finite mixed modeling (FMM). The statistical approaches developed facilitated the detection of Immunoglobulin G (IgG) antibodies to H. pylori, C. jejuni, Toxoplasma gondii, hepatitis A virus, rotavirus and noroviruses (VA387 and Norwalk strains) in fifty-four diagnostically characterized plasma samples. Of the characterized samples, the detection rate was 87.5% for H

  14. Evaluation of a Combination Rapid Immunoassay for Detection of Giardia and Cryptosporidium Antigens

    PubMed Central

    Chan, Raymond; Chen, Jing; York, Mary K.; Setijono, Norman; Kaplan, Raymond L.; Graham, Fitzroy; Tanowitz, Herbert B.

    2000-01-01

    A combination cassette format nonenzymatic rapid immunoassay for detection of Giardia and Cryptosporidium antigens was evaluated by using 556 patient stool specimens from three clinical laboratories. This assay (Genzyme Diagnostics Contrast Giardia/Cryptosporidium), which can be used with fresh or formalin-fixed specimens, had unadjusted sensitivities and specificities of 96.1 and 98.5% for Giardia and 100 and 98.7% for Cryptosporidium, respectively, in this study. PMID:10618122

  15. A dissociative fluorescence enhancement technique for one-step time-resolved immunoassays

    PubMed Central

    Mukkala, Veli-Matti; Hakala, Harri H. O.; Mäkinen, Pauliina H.; Suonpää, Mikko U.; Hemmilä, Ilkka A.

    2010-01-01

    The limitation of current dissociative fluorescence enhancement techniques is that the lanthanide chelate structures used as molecular probes are not stable enough in one-step assays with high concentrations of complexones or metal ions in the reaction mixture since these substances interfere with lanthanide chelate conjugated to the detector molecule. Lanthanide chelates of diethylenetriaminepentaacetic acid (DTPA) are extremely stable, and we used EuDTPA derivatives conjugated to antibodies as tracers in one-step immunoassays containing high concentrations of complexones or metal ions. Enhancement solutions based on different β-diketones were developed and tested for their fluorescence-enhancing capability in immunoassays with EuDTPA-labelled antibodies. Characteristics tested were fluorescence intensity, analytical sensitivity, kinetics of complex formation and signal stability. Formation of fluorescent complexes is fast (5 min) in the presented enhancement solution with EuDTPA probes withstanding strong complexones (ethylenediaminetetra acetate (EDTA) up to 100 mM) or metal ions (up to 200 μM) in the reaction mixture, the signal is intensive, stable for 4 h and the analytical sensitivity with Eu is 40 fmol/L, Tb 130 fmol/L, Sm 2.1 pmol/L and Dy 8.5 pmol/L. With the improved fluorescence enhancement technique, EDTA and citrate plasma samples as well as samples containing relatively high concentrations of metal ions can be analysed using a one-step immunoassay format also at elevated temperatures. It facilitates four-plexing, is based on one chelate structure for detector molecule labelling and is suitable for immunoassays due to the wide dynamic range and the analytical sensitivity. Figure   PMID:21161513

  16. Cytomegalovirus Antibody in Cerebrospinal Fluid of Schizophrenic Patients Detected by Enzyme Immunoassay

    NASA Astrophysics Data System (ADS)

    Fuller Torrey, E.; Yolken, Robert H.; Winfrey, C. Jack

    1982-05-01

    By means of enzyme immunoassay techniques to detect the presence of antibody to cytomegalovirus, the cerebrospinal fluid of 178 patients with schizophrenia, 17 patients with bipolar disorders, and 11 other psychiatric patients was compared with that of 79 neurological patients and 41 normal control subjects. The cerebrospinal fluid of 20 of the schizophrenic patients and 3 of the patients with bipolar disorders showed significant increases in immunoglobulin M antibody to cytomegalovirus; no difference was found in patients on or off psychotropic medications.

  17. Automation of the enzyme immunoassay for the serodiagnosis of infectious diseases in cattle

    SciTech Connect

    Seawright, G.L.; Sanders, W.M.; Bryson, M.

    1980-01-01

    The enzyme immunoassay (EIA) is a versatile and highly sensitive new tool that can be used to detect a wide variety of infectious diseases or toxic agents and other low molecular weight compound. The paper describes the present state of development of the EIA-modified Technicon Autoanalyzer II instrumentation, standardization of quality control criteria for the automated EIA and standardization of the diagnostic decision process. (ACR)

  18. Improving of enzyme immunoassay for detection and quantification of the target molecules using silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Syrvatka, Vasyl J.; Slyvchuk, Yurij I.; Rozgoni, Ivan I.; Gevkan, Ivan I.; Overchuk, Marta O.

    2014-02-01

    Modern routine enzyme immunoassays for detection and quantification of biomolecules have several disadvantages such as high cost, insufficient sensitivity, complexity and long-term execution. The surface plasmon resonance of silver nanoparticles gives reasons of creating new in the basis of simple, highly sensitive and low cost colorimetric assays that can be applied to the detection of small molecules, DNA, proteins and pollutants. The main aim of the study was the improving of enzyme immunoassay for detection and quantification of the target molecules using silver nanoparticles. For this purpose we developed method for synthesis of silver nanoparticles with hyaluronic acid and studied possibility of use these nanoparticles in direct determination of target molecules concentration (in particular proteins) and for improving of enzyme immunoassay. As model we used conventional enzyme immunoassays for determination of progesterone and estradiol concentration. We obtained the possibility to produce silver nanoparticles with hyaluronan homogeneous in size between 10 and 12 nm, soluble and stable in water during long term of storage using modified procedure of silver nanoparticles synthesis. New method allows to obtain silver nanoparticles with strong optical properties at the higher concentrations - 60-90 μg/ml with the peak of absorbance at the wavelength 400 nm. Therefore surface plasmon resonance of silver nanoparticles with hyaluronan and ultraviolet-visible spectroscopy provide an opportunity for rapid determination of target molecules concentration (especial protein). We used silver nanoparticles as enzyme carriers and signal enhancers. Our preliminary data show that silver nanoparticles increased absorbance of samples that allows improving upper limit of determination of estradiol and progesterone concentration.

  19. Ultrasensitive Multiplexed Immunoassay for Tumor Biomarkers Based on DNA Hybridization Chain Reaction Amplifying Signal.

    PubMed

    Guo, Jinjin; Wang, Junchun; Zhao, Junqing; Guo, Zilin; Zhang, Yuzhong

    2016-03-23

    In this work, a novel electrochemical immunoassay protocol has been reported for simultaneous determination of multiple tumor biomarkers based on DNA hybridization chain reaction (HCR) for signal amplification. Alpha-fetoprotein (AFP) and prostate specific antigen (PSA) were selected as model biomarkers. The immunoassay protocol contained primary antibodies immobilized on gold nanoparticles (Au NPs), secondary antibodies conjugated with DNA concatemer from HCR of primer, auxiliary probe, and signal probe labeled with signal molecules (methyleneblue (MB) and ferrocene (Fc)). In the presence of target biomarkers, the sandwich immunocomplex was formed between the primary antibodies and secondary antibodies bioconjugates carrying numerous signal molecules. As a result, two well-resolved reduction peaks, one was at -0.35 V (corresponding to MB) and other was at 0.33 V (corresponding to Fc; both vs SCE), were obtained in differential pulse voltammetry, and peak currents changed were related to the level of biomarkers. Under optimal conditions, the electrochemical immunoassay exhibited a wide linear response range (0.5 pg mL(-1) to 50 ng mL(-1)) and low detection limits (PSA, 0.17 pg mL(-1); AFP, 0.25 pg mL(-1)) (at S/N = 3). In addition, the immunoassay was evaluated by analyzing simulate human serum sample, and the recoveries obtained were within 99.4-107.6% for PSA and 97.9-108.2% for AFP, indicating the immnuoassay could be applied to the simultaneous detection of AFP and PSA in human serum samples. PMID:26937717

  20. Magnetic luminescent nanoparticles as internal calibration for an immunoassay for ricin

    NASA Astrophysics Data System (ADS)

    Dosev, Dosi; Nichkova, Mikaela; Ma, Zhi-Ya; Gee, Shirley J.; Hammock, Bruce D.; Kennedy, Ian M.

    2008-02-01

    Fluorescence techniques rely on measurement of relative fluorescence units and require calibration to obtain reliable and comparable quantitative data. Fluorescent immunoassays are a very sensitive and convenient method of choice for rapid detection of biotoxins, such as ricin. Here we present the application of magnetic luminescent nanoparticles (MLNPs) with a magnetic core of Fe 3O 4 and a fluorescent shell of Eu:Gd IIO 3 as carriers for a nanobead-immunoassay for the detection of ricin with internal calibration. A sandwich immunoassay for ricin was performed on the surface of the MLNPs. The particles were functionalized with capture polyclonal antibodies. Anti-ricin antibodies labeled with Alexa Fluor dye were used as the detecting antibodies. After magnetic extraction, the amount of ricin bound to the particle surface was quantified and related to the fluorescence signal of the nanoparticles. In this new platform, the MLNPs have three main functions: (1) a probe for the specific extraction of the target analyte from the sample; (2) a carrier in the quantitative immunoassay with magnetic separation; and (3) an internal standard in the fluorescence measurement of the dye reporter. The MLNPs serve as an internal control for the total analysis including extraction and assay performance. This approach eliminates the experimental error inherent in particle extraction and measurement of absolute organic dye fluorescence intensities. All fluorescent measurements were performed in a microplate reader. The standard curve for ricin had a dynamic range from 20 ng/ml to 100 μg/ml with a detection limit of 5 ng/ml. The configuration that has been developed can be easily adapted to a high throughput miniaturized system.

  1. Comparison of methaqualone excretion patterns using Abuscreen ONLINE and EMIT II immunoassays and GC/MS.

    PubMed

    Brenner, C; Hui, R; Passarelli, J; Wu, R; Brenneisen, R; Bracher, K; ElSohly, M A; Ghodoussi, V D; Salamone, S J

    1996-05-17

    A study was performed to compare the ONLINE and EMIT II immunoassays with gas chromatographic/mass spectrometric (GC/MS) analysis of methaqualone metabolites on urine using samples obtained from a clinical study. Urine was collected over a 72 h period from six healthy adults (4 male, 2 female) after oral dosing with 200 mg methaqualone (MTQ). Each urine sample was analyzed by ONLINE and EMIT II. The samples were then analyzed by GC/MS, hydrolyzed with beta-glucuronidase and again analyzed by GC/MS. Both immunoassays showed greater than 600 ng/ml concentrations of drug in each sample by the second void and remained highly positive for the rest of the 72 h. Unhydrolyzed samples analyzed by GC/MS showed both low concentrations of MTQ as well as its five major hydroxylated metabolites. The hydrolyzed samples analyzed by GC/MS showed high concentrations of the hydroxylated metabolites with the 2'-hydroxy and 3'-hydroxy metabolites being present at the highest concentrations, the 4'-hydroxy metabolite at a lower amount and the 6-hydroxy and 2-hydroxy metabolites at the lowest concentrations. The GC/MS data coupled with the antibody cross-reactivity data indicate that the major species in clinical samples that cross-react in both immunoassays are the conjugated forms of the hydroxylated metabolites of MTQ. Therefore when confirming by GC/MS after an immunoassay screen it would be prudent to confirm for the major hydroxylated metabolites as glucuronides of MTQ instead of the parent drug. PMID:8635771

  2. Sensitive electrochemical immunoassay for 2,4,6-trinitrotoluene based on functionalized silica nanoparticle labels

    SciTech Connect

    Wang, Jun; Liu, Guodong; Wu, Hong; Lin, Yuehe

    2008-03-03

    We present a poly(guanine)-functionalized silica nanoparticle (NP) label-based electrochemical immunoassay for sensitively detecting 2,4,6-trinitrotoluene (TNT). This immunoassay takes advantage of magnetic bead–based platform for competitive displacement immunoreactions and separation, and use electroactive nanoparticles as labels for signal amplification. For this assay, anti-TNT-coated magnetic beads interacted with TNT analog-conjugated poly(guanine)-silica NPs and formed analog-anti-TNT immunocomplexes on magnetic beads. The immunocomplexes coated magnetic beads were exposed to TNT samples, which resulted in displacing the analog conjugated poly(guanine) silica NPs into solution by TNT. In contrast, there are no guanine residues releasing into the solution in the absence of TNT. The reaction solution was then separated from the magnetic beads and transferred to the electrode surface for electrochemical measurements of guanine oxidation with Ru(bpy)32+ as mediator. The sensitivity of this TNT assay was greatly enhanced through dual signal amplifications: 1) a large amount of guanine residues on silica nanoparticles is introduced into the test solution by displacement immunoreactions and 2) a Ru(bpy)32+-induced guanine catalytic oxidation further enhances the electrochemical signal. Some experimental parameters for the nanoparticle label-based electrochemical immunoassay were studied and the performance of this assay was evaluated. The method is found to be very sensitive and the detection limit of this assay is ~ 0.1 ng mL-1 TNT. The electrochemical immunoassay based on the poly[guanine]-functionalized silica NP label offers a new approach for sensitive detection of explosives.

  3. Multiplexed, Patterned-Paper Immunoassay for Detection of Malaria and Dengue Fever.

    PubMed

    Deraney, Rachel N; Mace, Charles R; Rolland, Jason P; Schonhorn, Jeremy E

    2016-06-21

    Multiplex assays detect the presence of more than one analyte in a sample. For diagnostic applications, multiplexed tests save healthcare providers time and resources by performing many assays in parallel, minimizing the amount of sample needed and improving the quality of information acquired regarding the health status of a patient. These advantages are of particular importance for those diseases that present with general, overlapping symptoms, which makes presumptive treatments inaccurate and may put the patient at risk. For example, malaria and dengue fever are febrile illnesses transmitted through mosquito bites, and these common features make it difficult to obtain an accurate diagnosis by symptoms alone. In this manuscript, we describe the development of a multiplexed, patterned paper immunoassay for the detection of biomarkers of malaria and dengue fever: malaria HRP2, malaria pLDH, and dengue NS1 type 2. In areas coendemic for malaria and dengue fever, this assay could be used as a rapid, point-of-care diagnostic to determine the cause of a fever of unknown origin. The reagents required for each paper-based immunoassay are separated spatially within a three-dimensional device architecture, which allows the experimental conditions to be adjusted independently for each assay. We demonstrate the analytical performances of paper-based assays for each biomarker and we show that there is no significant difference in performance between the multiplexed immunoassay and those immunoassays performed in singleplex. Additionally, we spiked individual analytes into lysed human blood to demonstrate specificity in a clinically relevant sample matrix. Our results suggest multiplex paper-based devices can be an essential component of diagnostic assays used at the point-of-care. PMID:27186893

  4. Detection of aerosolized biological agents by immunoassay followed by autonomous PCR confirmation

    SciTech Connect

    Dzenitis, J M; Hindson, B J; McBride, M T; Makarewicz, A J; Henderer, B D; Sathyam, U S; Smith, S M; Gutierrez, D M; Metz, T R; Venkateswaran, K S; Colston, B W; Farrow, S W

    2003-12-15

    An Autonomous Pathogen Detection System (APDS) unit is an automated, podium-sized system that monitors the air for all three biological threat agents (bacteria, viruses, and toxins). The system has been developed under the auspices of the U. S. Department of Energy and Department of Homeland Security by the University of California, Lawrence Livermore National Laboratory (LLNL) to protect people in critical or high-traffic facilities and at special events. The system performs continuous aerosol collection, sample preparation, and multiplexed biological tests using advanced immunoassays as the primary screen. Over ten agents are assayed at once, and results are reported hourly. R&D work this year focused on incorporating polymerase chain-reaction (PCR) techniques for detecting DNA as confirmation of immunoassay positives. The primary objective of the Dugway testing was to demonstrate the APDS with immunoassay identification and PCR confirmation of bacteria. A secondary objective was to demonstrate immunoassay identification of a protein toxoid (denatured toxin) aerosol release. A total of 12 agent trials were conducted over 14 days of testing, for a total of four work weeks at Dugway. Both testing objectives were achieved with multiple releases and clear identifications. The APDS was shown to be effective for identifying aerosolized Bacillus anthracis, Yersinia pestis, Bacillus globigii, and botulinum toxoid. The two areas for improvement were operational as opposed to hardware-related. The first was slowing the PCR thermal cycling to achieve stronger signals, which was demonstrated during the later phases of testing. The second area is to improve the parameters for autonomous PCR triggering; this is one of the focuses of the upcoming year's work.

  5. Pediatric donor cell leukemia after allogeneic hematopoietic stem cell transplantation in AML patient from related donor.

    PubMed

    Bobadilla-Morales, Lucina; Pimentel-Gutiérrez, Helia J; Gallegos-Castorena, Sergio; Paniagua-Padilla, Jenny A; Ortega-de-la-Torre, Citlalli; Sánchez-Zubieta, Fernando; Silva-Cruz, Rocio; Corona-Rivera, Jorge R; Zepeda-Moreno, Abraham; González-Ramella, Oscar; Corona-Rivera, Alfredo

    2015-01-01

    Here we present a male patient with acute myeloid leukemia (AML) initially diagnosed as M5 and with karyotype 46,XY. After induction therapy, he underwent a HLA-matched allogeneic hematopoietic stem cell transplantation, and six years later he relapsed as AML M1 with an abnormal karyotype //47,XX,+10[2]/47,XX,+11[3]/48,XX,+10,+11[2]/46,XX[13]. Based on this, we tested the possibility of donor cell origin by FISH and molecular STR analysis. We found no evidence of Y chromosome presence by FISH and STR analysis consistent with the success of the allogeneic hematopoietic stem cell transplantation from the female donor. FISH studies confirmed trisomies and no evidence of MLL translocation either p53 or ATM deletion. Additionally 28 fusion common leukemia transcripts were evaluated by multiplex reverse transcriptase-polymerase chain reaction assay and were not rearranged. STR analysis showed a complete donor chimerism. Thus, donor cell leukemia (DCL) was concluded, being essential the use of cytological and molecular approaches. Pediatric DCL is uncommon, our patient seems to be the sixth case and additionally it presented a late donor cell leukemia appearance. Different extrinsic and intrinsic mechanisms have been considered to explain this uncommon finding as well as the implications to the patient. PMID:25674158

  6. 76 FR 65735 - Draft Guidance for Industry: Implementation of Acceptable Abbreviated Donor History Questionnaire...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... Abbreviated Donor History Questionnaire and Accompanying Materials for Use in Screening Frequent Donors of... entitled ``Guidance for Industry: Implementation of Acceptable Abbreviated Donor History Questionnaire and.... The draft guidance document recognizes the abbreviated donor history questionnaire and...

  7. 21 CFR 1271.50 - How do I determine whether a donor is eligible?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.50 How do I... document the eligibility of a cell or tissue donor. (b) Eligible donor. A donor is eligible under...

  8. 21 CFR 1271.50 - How do I determine whether a donor is eligible?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.50 How do I... document the eligibility of a cell or tissue donor. (b) Eligible donor. A donor is eligible under...

  9. Novel one-step immunoassays to quantify α-synuclein: applications for biomarker development and high-throughput screening.

    PubMed

    Bidinosti, Michael; Shimshek, Derya R; Mollenhauer, Brit; Marcellin, David; Schweizer, Tatjana; Lotz, Gregor P; Schlossmacher, Michael G; Weiss, Andreas

    2012-09-28

    Familial Parkinson disease (PD) can result from α-synuclein gene multiplication, implicating the reduction of neuronal α-synuclein as a therapeutic target. Moreover, α-synuclein content in human cerebrospinal fluid (CSF) represents a PD biomarker candidate. However, capture-based assays for α-synuclein quantification in CSF (such as by ELISA) have shown discrepancies and have limited suitability for high-throughput screening. Here, we describe two sensitive, in-solution, time-resolved Förster's resonance energy transfer (TR-FRET)-based immunoassays for total and oligomeric α-synuclein quantification. CSF analysis showed strong concordance for total α-synuclein content between two TR-FRET assays and, in agreement with a previously characterized 36 h protocol-based ELISA, demonstrated lower α-synuclein levels in PD donors. Critically, the assay suitability for high-throughput screening of siRNA constructs and small molecules aimed at reducing endogenous α-synuclein levels was established and validated. In a small-scale proof of concept compound screen using 384 well plates, signals ranged from <30 to >120% of the mean of vehicle-treated cells for molecules known to lower and increase cellular α-synuclein, respectively. Furthermore, a reverse genetic screen of a kinase-directed siRNA library identified seven genes that modulated α-synuclein protein levels (five whose knockdown increased and two that decreased cellular α-synuclein protein). This provides critical new biological insight into cellular pathways regulating α-synuclein steady-state expression that may help guide further drug discovery efforts. Moreover, we describe an inherent limitation in current α-synuclein oligomer detection methodology, a finding that will direct improvement of future assay design. Our one-step TR-FRET-based platform for α-synuclein quantification provides a novel platform with superior performance parameters for the rapid screening of large biomarker cohorts and of

  10. Computer applications in the search for unrelated stem cell donors.

    PubMed

    Müller, Carlheinz R

    2002-08-01

    The majority of patients which are eligible for a blood stem cell transplantation from an allogeneic donor do not have a suitable related donor so that an efficient unrelated donor search is a prerequisite for this treatment. Currently, there are over 7 million volunteer donors in the files of 50 registries in the world and in most countries the majority of transplants are performed from a foreign donor. Evidently, computer and communication technology must play a crucial role in the complex donor search process on the national and international level. This article describes the structural elements of the donor search process and discusses major systematic and technical issues to be addressed in the development and evolution of the supporting telematic systems. The theoretical considerations are complemented by a concise overview over the current state of the art which is given by describing the scope, relevance, interconnection and technical background of three major national and international computer appliances: The German Marrow Donor Information System (GERMIS) and the European Marrow Donor Information System (EMDIS) are interoperable business-to-business e-commerce systems and Bone Marrow Donors World Wide (BMDW) is the basic international donor information desk on the web. PMID:12216954

  11. Transplantation and differentiation of donor cells in the cloned pigs

    SciTech Connect

    Shimada, Arata; Tomii, Ryo; Kano, Koichiro; Nagashima, Hiroshi . E-mail: hnagas@isc.meiji.ac.jp

    2006-06-02

    The application of nuclear transfer technology is an interesting approach to investigate stem and progenitor cell transplantation therapy. If stem cells are used as a nuclear donor, donor cells can engraft into cloned animals without histocompatible problems. However, it is still uncertain whether donor cells can engraft to cloned animal and differentiate in vivo. To address this problem, we transplanted donor cells to dermal tissues of cloned pigs developed by using preadipocytes as donor cells. Preadipocytes are adipocytic progenitor which can differentiate to mature adipocytes in vitro. We showed that the donor preadipocytes were successfully transplanted into the cloned pigs without immune rejection and they differentiated into mature adipocytes in vivo 3 weeks after transplantation. In contrast, allogenic control preadipocytes, which can differentiate in vitro, did not differentiate in vivo. These results indicate that donor progenitor cells can differentiate in cloned animal.

  12. Overextended Criteria Donors: Experience of an Italian Transplantation Center.

    PubMed

    Nure, E; Lirosi, M C; Frongillo, F; Bianco, G; Silvestrini, N; Fiorillo, C; Sganga, G; Agnes, S

    2015-09-01

    The increasing gap between the number of patients who could benefit from liver transplantation and the number of available donors has fueled efforts to maximize the donor pool using marginal grafts that usually were discarded for transplantation. This study included data of all patients who received decreased donor liver grafts between January 2004 and January 2013 (n = 218) with the use of a prospectively collected database. Patients with acute liver failure, retransplantation, pediatric transplantation, and split liver transplantation were excluded. Donors were classified as standard donor (SD), extended criteria donor (ECD), and overextended criteria donor (OECD). The primary endpoints of the study were early allograft primary dysfunction (PDF), primary nonfunction (PNF), and patient survival (PS), whereas incidence of major postoperative complications was the secondary endpoint. In our series we demonstrated that OECD have similar outcome in terms of survival and incidence of complication after liver transplantation as ideal grafts. PMID:26361653

  13. A Multiplex Immunoassay Method for Simultaneous Quantification of Iron, Vitamin A and Inflammation Status Markers

    PubMed Central

    Crudder, Christopher; Levin, Carol E.; Garrett, Dean; Lyman, Chris; Boyle, David S.

    2014-01-01

    Deficiencies of vitamin A and iron affect a significant portion of the world's population, and efforts to characterize patterns of these deficiencies are hampered by a lack of measurement tools appropriate for large-scale population-based surveys. Vitamin A and iron are not easily measured directly, so reliable proxy markers for deficiency status have been identified and adopted. Measurement of inflammatory markers is necessary to interpret vitamin A and iron status markers, because circulating levels are altered by inflammation. We developed a multiplex immunoassay method for simultaneous measurement of five markers relevant to assessing inflammation, vitamin A and iron status: α-1-acid glycoprotein, C-reactive protein, retinol binding protein 4, ferritin and soluble transferrin receptor. Serum and plasma specimens were used to optimize the assay protocol. To evaluate assay performance, plasma from 72 volunteers was assayed using the multiplex technique and compared to conventional immunoassay methods for each of the five markers. Results of the new and conventional assay methods were highly correlated (Pearson Correlations of 0.606 to 0.991, p<.0001). Inter-assay imprecision for the multiplex panel varied from 1% to 8%, and all samples fell within the limits of quantification for all assays at a single dilution. Absolute values given by the multiplex and conventional assays differed, indicating a need for further work to devise a new standard curve. This multiplexed micronutrient immunoassay technique has excellent potential as a cost effective tool for use in large-scale deficiency assessment efforts. PMID:25525806

  14. Magneto-actuated immunoassay for the detection of Mycobacterium fortuitum in hemodialysis water.

    PubMed

    Brugnera, Michelle Fernanda; Bundalian, Reynaldo; Laube, Tamara; Julián, Esther; Luquin, Marina; Zanoni, Maria Valnice Boldrin; Pividori, Maria Isabel

    2016-06-01

    This paper addresses a sensitive method for the detection of mycobacteria in hemodialysis water samples based on a magneto-actuated immunoassay with optical readout. In this approach, micro (2.8μm) sized magnetic particles were modified with an antibody against the lipoarabinomannan (LAM) located in the mycobacterial cell wall. The system relies on the immunocapturing of the mycobacteria with the tailored antiLAM magnetic particles to pre-concentrate the bacteria from the hemodialysis samples throughout an immunological reaction. The performance of the immunomagnetic separation on the magnetic carrier was evaluated using confocal microscopy to study the binding pattern, as well as a magneto-actuated immunoassay with optical readout for the rapid detection of the bacteria in spiked hemodialysis samples. In this approach, the antiLAM polyclonal antibody was labeled with fluorescein isothiocyanate. The optical readout was achieved by the incubation with a secondary anti-fluorescein antibody labeled with peroxidase as optical reporter. The magneto-actuated immunoassay was able to detect mycobacteria contamination in hemodialysis water at a limit of detection of 13CFUmL(-1) in a total assay time of 3h without any previous culturing pre-enrichment step. PMID:27130087

  15. Surface-enhanced Raman Immunoassay (SERIA): detection of Bacillus globigii in ground water

    NASA Astrophysics Data System (ADS)

    Guicheteau, Jason A.; Christesen, Steven D.

    2004-12-01

    This work presents the development of new methodologies centering on surfaces with immunologically induced affinities for biomaterials in aqueous systems. The immunologically active surfaces concentrate the biomaterials at the interface and therefore eliminate the need for preconcentration steps. This results in a highly sensitive and rapid immunoassay technique. The very strong localized of surface enhanced Raman scattering (SERS) that occurs at noble metal surfaces is combined with the unparalleled selectivity of immunoassays. Localization of the SERS signal eliminates the problem of washing and allows assays to be performed without treatment steps associated with removing excess agents. Previous work with small illicit drug molecules and large microorganisms clearly demonstrates trace detection of species in aqueous environments is possible. This paper discusses further work to detect Bacillus globigii by couping surface enhanced Raman scattering with immunoassays (SERIA) using citrate reduced silver nanoparticles. The spores of B. globigii are used to simulate the behavior of another bacterium that forms spores-the potential biological warfare agent, Bacillus anthracis, the causative agent of anthrax.

  16. Targeted Selected Reaction Monitoring Mass Spectrometric Immunoassay for Insulin-like Growth Factor 1

    PubMed Central

    Niederkofler, Eric E.; Phillips, David A.; Krastins, Bryan; Kulasingam, Vathany; Kiernan, Urban A.; Tubbs, Kemmons A.; Peterman, Scott M.; Prakash, Amol; Diamandis, Eleftherios P.; Lopez, Mary F.; Nedelkov, Dobrin

    2013-01-01

    Insulin-like growth factor 1 (IGF1) is an important biomarker of human growth disorders that is routinely analyzed in clinical laboratories. Mass spectrometry-based workflows offer a viable alternative to standard IGF1 immunoassays, which utilize various pre-analytical preparation strategies. In this work we developed an assay that incorporates a novel sample preparation method for dissociating IGF1 from its binding proteins. The workflow also includes an immunoaffinity step using antibody-derivatized pipette tips, followed by elution, trypsin digestion, and LC-MS/MS separation and detection of the signature peptides in a selected reaction monitoring (SRM) mode. The resulting quantitative mass spectrometric immunoassay (MSIA) exhibited good linearity in the range of 1 to 1,500 ng/mL IGF1, intra- and inter-assay precision with CVs of less than 10%, and lowest limits of detection of 1 ng/mL. The linearity and recovery characteristics of the assay were also established, and the new method compared to a commercially available immunoassay using a large cohort of human serum samples. The IGF1 SRM MSIA is well suited for use in clinical laboratories. PMID:24278387

  17. Production of anti-idiotype antibodies for deoxynivalenol and their evaluation with three immunoassay platforms.

    PubMed

    Maragos, C M

    2014-05-01

    Immunoassays for deoxynivalenol (DON) that involve binding to DON-specific antibodies have been widely developed. In such assays, the responses of samples are generally compared with calibration curves generated by using DON in competition with labeled reagents such as enzymatic or fluorescent conjugates of the toxin. However, materials that mimic the toxin can also be used, provided that they compete effectively with the labeled reagents for the DON-specific antibodies. Examples include certain types of anti-idiotype antibodies, obtained by the immunization of animals with toxin-specific antibodies. In the present work, anti-idiotype antibodies were developed which mimicked DON in the ability to bind to a DON-specific monoclonal antibody (Mab). Fab fragments of the Mab (Ab1) were used to immunize rabbits. Sera were screened by competitive direct enzyme linked immunosorbent assay (CD-ELISA) for the presence of anti-idiotype antibodies (Ab2). In order to determine the most effective screening format and also the potential efficacy in various forms of biosensors, the sera were further evaluated in biolayer interferometry (BLI) and fluorescence polarization immunoassay (FPIA) formats. All three formats were used to demonstrate the presence of anti-idiotypes capable of binding to the paratope of the DON antibody (subtypes Ab2β or Ab2γ). Such materials have the potential to replace DON as calibrants in immunoassays for this toxin. PMID:24526340

  18. Development of immunoassays using interferometric real-time registration of their kinetics.

    PubMed

    Orlov, A V; Burenin, A G; Shipunova, V O; Lizunova, A A; Gorshkov, B G; Nikitin, P I

    2014-01-01

    A method for effective development of solid-phase immunoassays on a glass surface and for optimization of related protocols by highly sensitive quantitative monitoring of each assay step has been proposed and experimentally implemented. The method is based on the spectral correlation interferometry (SCI) that allows real-time measuring of the thickness of a biomolecular layer bound to the recognition molecular receptors on the sensor chip surface. The method is realized with compact 3-channel SCI-biosensors that employ as the sensor chips standard cover glass slips without deposition of any additional films. Different schemes for antibody immobilization on a glass surface have been experimentally compared and optimized toward a higher sorption capacity of the sensor chips. Comparative characterization of the kinetics of each immunoassay stage has been implemented with the optimized protocols: i) covalent immobilization of antibody on an epoxylated surface and ii) biotinylated antibody sorption on a biotinylated surface via a high-affinity biotin-streptavidin bond. We have shown that magnetic nanoparticles employed as labels with model detection of cardiac troponin I further amplify the SCI signal, resulting in 100-fold improvement of the detection limit. The developed protocols can also be used with the alternative immunoassay platforms, including the label methods based on registration of only the final assay result, which is the quantity of bound labels. PMID:24772331

  19. Harmonization protocols for thyroid stimulating hormone (TSH) immunoassays: different approaches based on the consensus mean value.

    PubMed

    Clerico, Aldo; Ripoli, Andrea; Zucchelli, Gian Carlo; Plebani, Mario

    2015-02-01

    The lack of interchangeable laboratory results and consensus in current practices has underpinned greater attention to standardization and harmonization projects. In the area of method standardization and harmonization, there is considerable debate about how best to achieve comparability of measurement for immunoassays, and in particular heterogeneous proteins. The term standardization should be used only when comparable results among measurement procedures are based on calibration traceability to the International System of Units (SI unit) using a reference measurement procedure (RMP). Recently, it has been promoted the harmonization of methods for many immunoassays, and in particular for thyreotropin (TSH), as accepted RMPs are not available. In a recent paper published in this journal, a group of well-recognized authors used a complex statistical approach in order to reduce variability between the results observed with the 14 TSH immunoassay methods tested in their study. Here we provide data demonstrating that data from an external quality assessment (EQA) study allow similar results to those obtained using the reported statistical approach. PMID:25241732

  20. Sandwich Immunoassays of Multicomponent Subtrace Pathogenic DNA Based on Magnetic Fluorescent Encoded Nanoparticles

    PubMed Central

    Liu, Yaxu; Zhang, Xuanjun; E, Yifeng; Fang, Fang; Kuang, Guangkai; Wang, Guannan

    2016-01-01

    A novel magnetic fluorescent encoded nanoimmunoassay system for multicomponent detection and separation of the subtrace pathogenic DNA (hepatitis B virus surface gene, HBV; hepatitis A virus poly the protein gene, HAV) was established based on new type of magnetic fluorescent encoded nanoparticles and sandwich immunoassay principle. This method combines multifunctional nanoparticles, immunoassay technique, fluorescence labeling, and magnetic separation of multicomponent technology. It has many advantages such as high sensitivity, low detection limit, easy operation, and great potential for development. The results of this work show that, based on nanoimmunoassay system, it could quantitatively detect the multicomponent trace pathogenic HAV and HBV DNA, as well as detection limit up to 0.1 pM and 0.12 pM. Furthermore, with the improvement of the performances of magnetic fluorescent encoded nanoparticles, the sensitivity will be further improved. In this experiment, a new nanoimmunoassay system based on magnetic fluorescent encoded nanoparticles was established, which will provide a new way for the immunoassay and separation of multicomponent biomolecules. PMID:26881227