Simple and more sensitive immune complex transfer enzyme immunoassay for antibody IgG to reverse transcriptase of HIV-1 using microplates, modified polystyrene solid phase and fluororeader.

In a previously reported ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for antibody IgG to HIV-1, polystyrene beads in test tubes were handled with tweezers, and bound beta-D-galactosidase activity was measured with a fluorometer. The use of tweezers was causative of false-positivity by carryover, and testing many samples was difficult. Recently, these drawbacks have been minimized using microplates, a fluororeader, and modified polystyrene beads with sticks for easy handling. The modified polystyrene beads were transferred from wells to wells more quickly and easily without tweezers, eliminating false-positivity due to carryover. The fluorescence intensity for bound beta-D-galactosidase activity was quickly measured with a fluororeader. As a result, it became easy to test many samples with high reliability. However, modified polystyrene beads used were handmade, and the sensitivity was lower than the previous assay with test tubes. In the present study, the condition of the immune complex transfer enzyme immunoassay for antibody IgG to reverse transcriptase of HIV-1 was optimized using microplates, a fluororeader, and polystyrene solid phase with stick, which is commercially available. Testing many samples became easy with higher sensitivity.