EFFECTS OF ANTICOAGULANTS AND STORAGE OF BLOOD-SAMPLES ON EFFICACY OF THE POLYMERASE CHAIN-REACTION ASSAY FOR HEPATITIS-C VIRUS

Blood samples from 11 patients with posttransfusion hepatitis C virus infection were collected. Each sample was divided into three fractions to obtain sera, sodium-citrated plasma, and heparinized plasma and then tested for HCV RNA by a nested polymerase chain reaction (PCR). Of them, eight sodium-citrated plasma samples, seven serum samples, and no heparinized plasma samples were PCR positive. Eight PCR-positive sodium-citrated plasma samples were exposed to different physical conditions and semiquantified for HCV RNA after serial dilutions. Samples stored at -70-degrees-C showed the best preservation of HCV RNA, and storage at the other conditions resulted in only minimal loss of the PCR signal. Therefore, serum or sodium-citrated plasma specimens are satisfactory for detecting HCV RNA by PCR, but heparinized blood specimens are not.