Stable hepatitis C virus RNA detection by RT-PCR during four days storage -: art. no. 22

Background: Suboptimal specimen processing and storage conditions of samples which contain hepatitis C virus ( HCV) RNA may result in a decline of HCV RNA concentration or false-negative results in the detection of HCV RNA in serum. We evaluated the stability of HCV RNA in serum and clotted blood samples stored at room temperature or at 4degreesC for 4 days with the aim of optimizing the standard procedures of processing and storage of samples. Methods: Blood from five HCV RNA positive patients was collected in tubes with and without separator gel, centrifuged 1 or 6 hours after collection. Samples were then left 6, 24, 48, 72 or 96 h at room temperature (21.5-25.4degreesC) or at 4degreesC before determining their HCV RNA level using the COBAS AMPLICOR HCV MONITOR Test, vs 2.0 ( Roche Diagnostic Systems). Results: The logarithm of the HCV RNA level measurements remained within a 0.3 value of the means for 4 days at both temperatures ( room temperature or 4degreesC). Conclusions: We conclude that blood samples may be collected and aliquoted within 6 h of collection and can be stored at 4degreesC for 72 hours as proposed by the manufacturer without significant differences in measured HCV RNA level. Our results indicate that lapses in this scheme may still yield reliable results.