Comparison of the Abbott RealTime human immunodeficiency virus type 1 (HIV-1) assay to the Cobas ampliprep/cobas TaqMan HIV-1 test: Workflow, reliability, and direct costs

Cari R. Sloma, Jeffrey J. Germer, Tara M. Gerads, Jayawant Mandrekar, P. Shawn Mitchell, Joseph D C Yao

Research output: Contribution to journalArticle

35 Scopus citations


The Abbott RealTime human immunodeficiency virus type 1 (HIV-1) assay (ART) and the Cobas AmpliPrep/ Cobas TaqMan HIV-1 test (CTM) are commercially available assays for quantification of HIV-1 RNA in plasma. We evaluated performance characteristics, workflow, throughput, reliability, and direct costs of these assays. Both assays yielded good correlation of quantitative results (r = 0.95) among clinical specimens, with a mean difference of -0.34 log10 copies/ml. Testing of healthy donor plasma specimens yielded "target not detected" results by ART, with "HIV-1 RNA detected, <40 copies/ml" results for 3.3% (3 of 90 samples) of these specimens by CTM. Both the m2000sp/m2000rt (ART) and docked CAP/CTM96 (CTM) instrument systems were capable of operating with continuous, uninterrupted workflow. When daily maintenance and cleaning were included, ART and CTM run durations (5 h 52 min and 6 h 4 min, respectively) and hands-on times (53 min and 46 min, respectively) were similar for a run batch size of 24. While ART was more flexible in terms of run batch size, CTM required fewer user interventions and consistently produced higher specimen throughput rates at 8, 16, and 24 h. Assay run failure rates were 6.3% (1 of 16 runs) and 4.2% (1 of 24 runs) for ART and CTM, respectively (P = 1.000), with invalid specimen result rates of 1.0% (5 of 495 specimens) and 2.8% (11 of 399 specimens), respectively (P = 0.073). Direct reagent and consumable costs for each assay were comparable (difference of <10%). In selecting an assay for implementation, laboratories should consider how various assay and instrument features might impact laboratory operation and patient care.

Original languageEnglish (US)
Pages (from-to)889-895
Number of pages7
JournalJournal of Clinical Microbiology
Issue number4
StatePublished - Apr 2009


ASJC Scopus subject areas

  • Microbiology (medical)

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