Comparison of spot-blot and microtitre plate methods for the detection of HIV-1 PCR products

We have compared spot-blot methodology with a recently developed rapid microtitre plate assay for the specific detection of HIV-1 PCR products. We have studied blood specimens isolated from HIV-1 infected individuals (48 asymptomatic and 56 symptomatic patients). Mononuclear cells were isolated, lysed and processed for PCR. Both PCR product detection methods were carried out in parallel on all amplified samples. HIV-1 sequences were detected by spot-blot or microtitre plate hybridization in samples taken from 42/48 asymptomatic and 53/56 symptomatic subjects. Concordant results between the two detection methods were observed for 90 samples, with 81 positive and nine negative assays. On repeat evaluation of the 14 discordant samples, nine showed concordant positive results, near the limit of detection of the assay. Serial dilutions of ACH-2 cells were amplified, and the PCR products were detected using the microtitre plate assay, yielding semi-quantitative results. The sensitivity of this simple, rapid assay compares with that of more laborious DNA detection systems. This may become a useful tool in HIV-1 research and in the clinical care of seropositive individuals.