Reproducibility and performance of the second-generation branched-DNA assay in routine quantification of human immunodeficiency virus type 1 RNA in plasma

We examined the reproducibility of a second-generation branched-DNA (bDNA) assay (Quantiplex HIV RNA 2.0) for quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma by retesting 325 specimens on separate runs and on different lots. The performance of the bDNA test was also assessed by data analysis obtained during routine testing of 15,365 specimens. Upon retesting, 96 and 86% of specimens displaying RNA levels above 5,000 and between 500 and 5, 000 copies/ml, respectively, showed less than a 0.3 log10 (twofold) difference with their initial values. Assay variability was found to increase as viral load decreased. Overall, the bDNA version 2.0 assay was found to be a reproducible and efficient test for routine quantification of HIV-1 RNA in plasma.