Songsivilai, SirirurgLuangwedchakarn, VoravichKanistanon, DuangjitLouisirirotchanakul, SudaDharakul, Tararaj2012-04-272012-04-271993-09Songsivilai Sirirurg, Luangwedchakarn Voravich, Kanistanon Duangjit, Louisirirotchanakul Suda, Dharakul Tararaj. Detection of hepatitis C virus RNA by polymerase chain reaction: Design of amplification primers. Siriraj Medical Journal, 1993 Sept; 45(9): 597-603.http://imsear.searo.who.int/handle/123456789/138009New sets of primers for amplification of hepatitis C virus (HCV) RNA were designed from the conserved regions of American and Japanese isolates of HCV. Primers set A amplified parts of the 5’-untranslated and core gene regions, whereas set B amplified parts of the core and envelope gene regions. PCR amplification were carried out from HCV RNA isolated from sera of 13 Thai patients with antibody to HCV, using these newly developed primers. HCV RNA was detectable in 8 patients (61.5%). Of those PCR positive samples, only 4 patients (50%) were positive with primer set A, whereas 7 patients (87.5%) were positive with primer set B. Interestingly, 4 patients were tested positive with only set B, 3 patients with both sets A and B, and just one patient with set A only. This result suggests that PCR assay as a diagnostic tool for HCV may need to be carried out with more than one primer set. The relatively low percentage of PCR positivity of the HCV from Thai patients using primer set A, which was previously identified as the most conserved region of the HCV genome, also indicates that the sequence of the Thai isolates of the virus may be different from those of the American and Japanese strains.enHepatitis C virus RNAPolymerase chain reactionArticle