ABSTRACT
【Objective】 To investigate NAT non-reactive results implicated in HBsAg ELISA reactive voluntary blood donors in Shenzhen. 【Methods】 HBsAg ELISA+ but NAT-blood samples were collected, and HBsAg was further retested by TRFIA, Roche ECLIA and neutralization test. HBV DNA of individual donation was detected by commercial Roche MPX and Uultrio Elite, and virus nucleic acid was extracted via 2.5 mL. Molecular characterizations of HBsAg+ /NAT-samples were determined by quantitative polymerase chain reaction(qPCR) and nested PCR amplifification of the precore and core promoter regions and HBsAg(S) region. HBV serological markers were detected, and the samples with suspicious results were followed up and detected by multi-assay. 【Results】 Among 67 602 samples, 73(0.11%) HBsAg ELISA+ and NAT-blood samples were enrolled in the study. 15(20.5%, 15/73) were confirmed HBsAg+ by TRFIA, ECLI and five alternative DNA assays, and the other 2(2.7%, 2/73) were further identified as HBsAg+ by follow-up study. In 17 confirmed HBsAg+ samples, the viral loads ranged undetectable to 378 IU/mL, with the median of 10.1 IU/mL. Weak correlation was found between HBsAg and HBV DNA load(R2=0.394 4). 【Conclusion】 Some Hepatitis B virus infected blood samples may miss even with different HBsAg assays. Multi-assays with high sensitivity should be combined for blood screening to ensure blood safety..The inconsistent results should be followed up and further tested for hepatitis B serological markers to assist the confirmation.
ABSTRACT
Objective To develop a kit of time?resolved fluoroimmunoassay(TRFIA)for detection of Schistosoma japonicum protein SjP38,and evaluate its effectiveness. Methods The anti 9G7 SjP38 monoclonal antibody was used as the capture anti?body coated with 96?hole plate,and the Eu3+labeled 1A6 monoclonal antibody was used as the detection antibody to establish the TRFIA SjP38 kit. In addition,the accuracy,sensitivity,precision,stability and coincidence rate to pathogenic diagnosis of the kit were evaluated. Results This established kit possessed high accuracy,wide linear range from 2 to 1 250 ng/ml,high sensitivity with the minimum detectable concentration of 0.14 ng/ml,and good precision(the coefficient variation of the intra?and inter?assay were 3.6%to 4.6%and 5.1%to 6.7%,respectively). The stability tests showed that the reagents could be stable for six months at 4℃,7 d at 37℃. The positive and negative corresponding rates to the pathogen detection method were 95%and 100%respectively. Conclusion All the performance and detection indicators of the kit have reached the requirements of clinical test,but its clinical application still needs further validation.
ABSTRACT
Objective To investigate the application of time‐resolved fluorescence immunoassay (TRFIA) in the detection of specific antibody of syphilis .Methods Specific antibody of syphilis was detected in serum samples of 240 cases of syphilis and 150 healthy subjects by TRFIA ,Treponemal pallidum particle agglutination(TPPA) and Treponemal pallidum enzyme linked immu‐nosorbent assay(TP‐ELISA) .The sensitivity ,specificity and positivity of these three methods were compared .Results The sensi‐tivity of TRFIA ,TP‐ELISA ,TPPA were 100 .00% ,98 .75% and 97 .92% ,without significantly differences(P>0 .05) ,and the spe‐cificity were 99 .33% ,98 .67% and 100 .00% .The false positive rate of TRFIA was 0 .67% ,and the false negative rate was 0 .00% . The false positive rate of TP‐ELISA was 1 .33% ,and the false negative rate was 1 .25% .False positive rate and false negative rate of TRFIA were lower than TP‐ELISA(P<0 .05) .Conclusion TRFIA could be with high sensitivity and specificity in syphilis spe‐cific antibody test ,and could be used for routine screening of syphilis specific antibody .
ABSTRACT
The acticle describes a time—resolved fluoroimmunoassay for serum progesterone,based ona competitive solid—phase antigen technique。Progesterone—BSA conjugates are coated onto thewhite opaque microtitration wells。Anti—progesterone antibody is biotinylated.Eu~(3+) are labelledto streptavidin as the tracer.The assay standard curve covers a range of 0.1—100ng/ml.Thelowest detecting limit is 0.05ng/ml。The intra and inter C?V s are 6.45% and 8.93% respec-tively.The average recovery is 89.5%.40woman samples are measured with RIA and presentTRFIA and the results are satisfactory,giving a correlation coefficient of 0.9619.The perfor-mance charicter—istics of the assay are discussed and compared with other known immunoas-says.