COMPARABLE SENSITIVITIES FOR DETECTION OF HIV-1 REVERSE-TRANSCRIPTASE(RT) AND OTHER POLYMERASES BY RT ASSAYS REQUIRING NO RADIOISOTOPIC MATERIALS

An improved non-radioisotopic (Non-RI) reverse transcriptase (RT) assa y with a template-primer-immobilized microtiter plate is described, wh ich has greater sensitivity than the former Non-RI RT assay previously described. Non-RI and commercially available non-radioactive (Non-RA) RT assays were compared for their ability to detect various polymeras es. Two RTs from Rous-associated virus 2 (RAV-2) and avian myeloblasto sis virus (AMV), one polymerase from Escherichia coli (Pol-I) and one recombinant RT of human immunodeficiency virus type 1 (HIV-1) were ass essed. Two HIV-1 samples in a culture supernatant and pelleted virion suspended in Triton X-100 solution were measured. The Non-RI RT assay was one hundred times more sensitive by RAV-2 and Pol-I polymerases, a nd one thousand times more sensitive by the Non-RA assay than by the A MV RT. The Non-RI RT assay was 10, 16 and 64 times more sensitive than the Non-RA assay for measuring recombinant HIV-1 RT, pelleted virus a nd virus suspended in culture medium, respectively. To explain the dis crepancy, it is shown that free biotin, such as in culture medium, dis turbs the assay system of the Non-RA RT assay, but not the Non-RI assa y. The present assay can be used to clarify the inhibitory mechanism o f an anti-HIV-1 substance.