In Trang An polyclinics in Ha Noi, with ELISA technique, 35 healthy people (27 female aged 20-38, 8 male aged 25-37) undergone an examination of serum CA153-3 and 31 other healthy people (17 female aged 21-38, 14 male aged 22-41) an examination of resum CA125. The technique is complicated needing precaution and accuracy; for each examination, it is recommended a standard graphic with a standard sample determined antigen concentration. CA15-3 normal concentration is 2.37-18.17 U/ml, and CA125 is 7.17-38.37 U/ml
Enzyme-Linked Immunosorbent Assay ; methods ; serum

OBJECTIVETo identify a cost-efficient alternative antibody testing strategy for screening and confirmation of HIV infection by rapid simple tests (RSTs) and enzyme-linked immunosorbent assays (ELISAs).

METHODSFour RSTs (RST1, RST2, RST3, and RST4) and five ELISAs (ELISA1, ELISA2, ELISA3, ELISA4, and ELISA5) were evaluated in two phases by using banked and serum specimens prospectively collected at regional hospitals and voluntary counseling and testing (VCT) centers in Beijing. A total of 200 banked serum specimens were included in the first phase, including 62 HIV-positive, 127 HIV-negative and 11 indeterminate specimens. All specimens were tested by four RSTs and five ELISAs respectively. The second phase involved prospective testing of 389 routine specimens, including 92 HIV-positive, 287 HIV-negative, and 10 indeterminate specimens. All the specimens were tested by two RSTs (RST2 and RST4) and three ELISAs (ELISA1, ELISA3, and ELISA4), which were selected for their respective excellent sensitivity and/or specificity. Western blot (WB) was used as a gold standard for confirming the reactivity of all the specimens.

RESULTSSensitivity, specificity, and efficacy were calculated for each assay in two phases. In the first phase, four assays (ELISA4, RST2, RST3, and RST4) had a specificity of 100%. For the determination of efficacy, ELISA4, RST2, and RST4 were selected in the second phase. ELISA1 and ELISA3 which have a sensitivity of 95.9% and 93.2% respectively also entered this phase. In the second phase, all the five assays (ELISA1, ELISA3, ELISA4, RST2, and RST4) had a sensitivity and specifity of over 90%. ELISA1 had a sensitivity of 99% and ELISA4 a specificity of 99%.

CONCLUSIONThe sensitivity ELISA1 and the specificit of ELISA4 are comparable to ELISA/WB standard strategy. Application of this alternative testing strategy provides a cost-effective method for determining HIV prevalence in Beijing.

Blotting, Western ; methods ; China ; Enzyme-Linked Immunosorbent Assay ; methods ; HIV Infections ; diagnosis ; Humans ; Sensitivity and Specificity

OBJECTIVETo evaluate chemiluminescent immunoassay (CLIA), electrochemiluminescent immunoassay (ECLIA) and ELISA in determination of low level HBsAg.

METHODSAccording to the standard of CLIA Architect i2000, 70 samples were divided into three groups by HBsAg concentration : <1 ng/ml, 1-5 ng/ml and >4 ng/ml. The samples were also determined by ECLIA MODULAR170 and ELISA, and the results were compared with those measured by CLIA Architect i2000.

RESULTSThe concordance rates of ECLIA MODULAR170 with Architect i2000 was 79.2% for <1 ng/ml group, 100% for 1-5 ng/ml group, 100% for >4 ng/ml group. And the concordance rates of ELISA with Architect i2000 was 0 % for <1 ng/ml group, 45.5% for 1-5 ng/ml group and 100 % for >4 ng/ml group.

CONCLUSIONFor determination of low level HBsAg,CLIA Architect i2000 and ECLIA MODULAR170 have high credibility. ELISA is also credible when HBsAg >5 ng/ml, but not for low level HBsAg, especially for HBsAg <1 ng/ml.

Enzyme-Linked Immunosorbent Assay ; Hepatitis B Surface Antigens ; blood ; Humans ; Immunoassay ; methods ; Luminescent Measurements ; methods

In the present study, quids from La Cueva de los Muertos Chiquitos (CMC) were subjected to ELISA tests for 2 protozoan parasites, Toxoplasma gondii (n=45) and Trypanosoma cruzi (n=43). The people who occupied CMC, the Loma San Gabriel, lived throughout much of present-day Durango and Zacatecas in Mexico. The known pathoecology of these people puts them into at-risk categories for the transmission of T. gondii and T. cruzi. Human antibodies created in response to these 2 parasites can be detected in modern saliva using ELISA kits intended for use with human serum. For these reasons, quids were reconstituted and subjected to ELISA testing. All test wells yielded negative results. These results could be a factor of improper methods because there is no precedence for this work in the existing literature. The results could equally be a simple matter of parasite absence among those people who occupied CMC. A final consideration is the taphonomy of human antibodies and whether or not ELISA is a sufficient method for recovering antibodies from archaeological contexts. An additional ELISA test targeting secretory IgA (sIgA) was conducted to further examine the failure to detect parasite-induced antibodies from quids. Herein, the methods used for quid preparation and ELISA procedures are described so that they can be further developed by future researchers. The results are discussed in light of the potential future of quid analysis.
Antibodies ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin A, Secretory ; Loma ; Methods ; Mexico ; Parasites ; Saliva ; Toxoplasma ; Trypanosoma cruzi

OBJECTIVETo prepare the antibodies against salbutamol (SAL) with high sensitivity and to develop an indirect competitive enzyme-linked immunoassay (ic-ELISA) for fast detection of SAL.

METHODSThe New Zealand white rabbits were immunized with SAL in a small dose and long period mode. The method of ic-ELISA was optimized and adopted for the detection of a series of SAL samples, then the standard curve of SAL was established. The precision and the recoveries of the method were determined.

RESULTSThe antibodies with high sensitivity towards SAL were prepared with a IC50 of 12.21 ng/ml. The ic-ELISA method for SAL measurement was established, the recoveries of measurement was between 95%-105% and the CV was <3%.

CONCLUSIONThe antibodies against salbutamol have been prepared and an indirect competitive enzyme-linked immunoassay for fast and specific detection of SAL has been developed.

Albuterol ; analysis ; immunology ; Animals ; Antibodies ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Male ; Rabbits

OBJECTIVETo establish the method of enzyme-linked immunosorbent assay (ELISA) for measuring human IgM autoantibody to folate receptor.

METHODSFolate receptor was extracted and purified from the healthy woman placenta. The protein was coated on 96-well plates with a concentration of 5 ng/Μl. Goat monoclonal antibody was used for detecting antibody. Pooled plasma from healthy donors was used to plot the standard curve and the IgM concentration of pooled plasma was defined as 1. We set up an ELISA procedure to measure human IgM autoantibody to folate receptor. The sensitivity, precision, and stability of the method were evaluated. Further, the folate receptor and bovine folate-binding protein were used as the antigen, respectively, to determine the autoantibody levels in 24 healthy individuals and 20 individuals once gave birth to baby with neural tube defects.

RESULTSThe measuring range of the method was from 6.25 × 10⁻⁴ to 8.00 × 10⁻². The lowest IgM level that can be detected was 3.12 × 10⁻⁴. The inter-assay coefficients of variations for samples with high, medium, and low IgM levels were 6.61%,3.50%, and 5.12%, respectively. The intra-assay coefficients of variations were 4.54%, 5.49%, and 5.44%, respectively. The stability test results were considered within acceptable limits. The data from folate receptor-ELISA was significantly higher than that from bovine folate binding protein-ELISA, both in the healthy group (t=-11.9, P<0.001) and in the neural tube defect group (t = 7.35, P<0.001).

CONCLUSIONSThe folate receptor-ELISA method for measuring human IgM autoantibody to folate receptor was successfully established. The method is sensitive, repeatable, and stable.

Autoantibodies ; blood ; Enzyme-Linked Immunosorbent Assay ; methods ; Folate Receptor 2 ; immunology ; Humans ; Immunoglobulin M ; blood

A simple and cost-effective indirect competitive enzyme-linked immune sorbent assay (ic-ELISA) was developed to rapidly screen the content of aflatoxin B1 (AFB1) in lotus seeds, and the results were confirmed by ultra-fast liquid chromatography-tandem mass spectrometry( UFLC-MS/MS). Matrix-matched calibration expressed a good linearity ranging from 0. 171 to 7. 25 µg · L(-1) for AFB, with R2 > 0.978. The medium inhibitory concentration( IC50 ) for AFB1 was 1.29 µg · L(-1), the recovery for AFB1 was 74.73% to 126.9% with RSD < 5%, and the limit of detection (IC10) was 0.128 µg · L(-1). The developed ic-ELSIA method was applied to rapid analysis of AFB, in 20 lotus seeds samples and the results indicated that the contents of AFB, in samples 1-15 were in the range of 1. 19- 115. 3 µg · kg(-1) and in 40% of the samples exceeded the legal limit(5 µg · kg(-1)), while the contamination rate of AFB, in samples 16-20 was 40%. Pearson correlation coefficient(r) reached 0.997 for AFB1 content in the samples detected by ic-ELSIA and UFLC-MS/MS methods. The results proved that the developed ic-ELISA method is simple, sensitive and reliable, and can be used for rapid and high-throughput screening of AFB1 in lotus seeds
Aflatoxin B1 ; analysis ; Drug Contamination ; Enzyme-Linked Immunosorbent Assay ; methods ; Loteae ; chemistry ; Seeds ; chemistry

Due to the high variation in test results of indirect enzyme-linked immuno sorbent assay (ELISA) and complicated steps involved in the process of standardization, a platform used for standardizing the test results from indirect ELISA was developed. The platform was designed based on 'Improved Standardization Method for Optical Density' (I-STOD). Gauss-Newton iteration was applied to estimate parameters in a standard formula. Programming Language VB was used for developing interface of platform. The results indicated that the validity of experiment could be verified through platform. A well determined scope of standardization could be generated. The sample with concentration within the scope was standardized and the degree of dilution was calculated for those outside the scope. The platform was successfully developed which normalized the process of standardization. The function provides the researchers with an effective and convenient tool for quickly achieving standardization of ELISA test results.
Antibodies ; analysis ; Enzyme-Linked Immunosorbent Assay ; methods ; standards ; Humans ; Optical Phenomena

OBJECTIVETo establish an ELISA approach to study the interaction of polysaccharides with cytokine in vitro.

METHODSThe heparin BSA complexes (HBC) were synthesized with a chemistry method and separated using a 1 X 90 cm column of Separose 4B. After identification of the complex via SDS-PAGE,the wells of ELISA plates were coated with HBC and the interaction of HBC with interferon-gamma (IFN-gamma) was detected. The effects of heparin, low molecular weight heparin (LMW heparin), chondroitin sulfate (CS), hyaluronic acid (HA) and carrageenans on the binding of HBC to IFN-gamma were tested in this system.

RESULTHuman recombinant IFN-gamma bound to heparin in a concentration dependent manner, the binding of IFN-gamma to HBC was detected at the concentration of 0.25 ng, and saturated at around 2 ng. Free heparin, LMW heparin, CS,HA and carrageenans competed for the binding of IFN-gamma to HBC with significant different ability. The IC(50)concentrations of heparin and LMW heparin were 2.40 microg/ml and 18.60 microg/ml respectively.

CONCLUSIONIFN-gamma is a cytokine with high binding affinity to heparin and carrageenans family but poor to CS-A and CS-C. ELISA is a simple, sensitive approach to detect the interaction of polysaccharides with cytokine in vitro.

Enzyme-Linked Immunosorbent Assay ; methods ; Heparin ; metabolism ; Interferon-gamma ; metabolism ; Polysaccharides ; metabolism ; Serum Albumin, Bovine ; metabolism

OBJECTIVESTo develop and evaluate a method for detection of the total antibodies against hemorrhagic fever with renal syndrome (HFRS) virus with improved sensitivity and simplified operation procedure.

METHODSThe nucleic proteins of hantavirus were used as coating antigens as well as detection antigens labeled with horse radish peroxidase (HRP). The operation protocol was established, optimized and compared with indirect fluorescence assay (IFA).

RESULTSThe specificity of this method was 100 percent in the test of different human sera and 4-8 times more sensitive than IFA. And, it is simpler without requiring any change of the reagents, different sources of samples did not affect the results of the test.

CONCLUSIONThis method is specific, sensitive and simple for detection of the total antibodies in sera against hantavirus, could be used for the screening of Hantavirus infection in human and host rodent animals.

Antibodies, Viral ; blood ; Enzyme-Linked Immunosorbent Assay ; methods ; Hantaan virus ; immunology ; Humans ; Reproducibility of Results ; Sensitivity and Specificity