Antigen sandwiched ELISA for detection of total HIV antibodies

Objective To establish a sensitive antigen sandwiched ELISA(AS) for detection of the total antibodies to HIV-1/2. Methods Based on the gene sequence of HIV-1/2 type and its coded amino acid structure,5 polypeptides were synthesized as coated antigens using solid-phase method. These polypeptides were labelled with horseradish peroxidase. And the total antibodies of HIV-1/2 were detected with the same method. Results These reagents were detected by three batches of HIV panel from The National Institute for the Control of Pharmaceutical and Biological Products (NICPBP). The results indicated that the corresponding rate was 100 %. The variant coefficient rate was less than 10 %. A comparison of antigen sandwiched ELISA with indirect ELISA in detection of a panel(20 positive sera and 20 negative sera) from the NICPBP showed that the general coincident rate of indirect ELISA was 92.5 % and the sandwiched system was 100 %. The HIV-AS diagnostic reagent kits have passed the quality examination of NICPBP. A comparison of antigen sandwiched ELISA with Yapei reagents in detection of 90 normal sera and 88 positive sera for HIV-1/2 showed that the coincident rate was 100%. The reagents were stable at 37℃ for 4 days. This indicated that our reagents were highly specific, sensitive and stable. Conclusion Our antigen sandwiched ELISA reagent for total antibodies of HIV has a merit of sensitivity specificity and stability. It can be clinically used for detection of HIV-1/2 infection and in blood bank for the screening of blood donors.