Reliability at the lower limits of HIV-1 RNA quantification in clinical samples: a comparison of RT-PCR versus bDNA assays.

Introduction: To explore whether an assay change was responsible for an increasing proportion of patients with undetectable HIV viral loads at our urban HIV clinic, we selected highly stable patients, examining their viral loads before and after changing assays. We compared the proportion with detectable viremia during RT-PCR vs. bDNA periods.