<正> The sensitivity of PCR was determined for detection of HBV DNA in paraffin-embed-ded liver tissue with different methods for sample preparation.Of 8 cases of HBeAg-positiveHBV infection

HBV DNA was detected in 6 by extracting DNA from both frozen and dewaxedsamples

but in none by direct reaction.Of 12 cases subjected to Southern blot hybridization

HBV DNA was detected in 7 by this technique

in 10 by PCR with both methods of DNA extrac-tion and in 3 by direct PCR.The results showed that PCR was sensitive and was comparablewith blot hybridization in detecting intrahepatic HBV DNA.In comparison between differentmethods of sample preparation

the viral detection rate from the dewaxed samples was near thatfrom the frozen ones

while by the direct reaction HBV DNA could be detected only in a fewsamples with high level of infection.