Abstract: To study transfusion transmitted virus(TTV)infection from liver tissues, double-strand and single-strand probes were labelled with digoxigenin to detect 56 liver samples by in situ hybridization and by symmetrical and unsymmetrical polymerase chain reaction(PCR). TTV DNA was found in 14 of 51 patients with non hepatitis A and non-hepatitis G(27.5%). Five liver samples without hepatitis were negative. TTV DNA was mainly observed in nuclei of hepatocytes and distributed in the tissues with acute, chronic and severe types of hepatitis. The hybridization result by double-strand probe was consistent with TTV genome strand hybridization by single-strand probe. In 2 of 6 liver samples were present both TTV genome strand and complementary strand. This study indicates that TTV is a novel virus which results in hapetitis and the virus replicates in liver tissue of the patients.

Key words: hepatitis virus, in situ hybridization, transfusion transmitted virus