Detection of hepatitis B virus DNA in serum by polymerase chain reaction

Standard methods of virus DNA detection using the polymerase chain reaction can be time consuming and can involve multiple steps in which contamination with exogenous DNA can occur. Therefore, we developed a simplified method for detecting hepatitis B virus DNA in serum. The main advantages of this method are that it can be performed rapidly, consists of only several steps, and has a false positive rate of less than 0.1% in our laboratory. In testing serial samples from five chimpanzees experimentally infected with hepatitis B virus, we found that hepatitis B virus DNA was detected 2-3 weeks before the appearance of hepatitis B surface antigen, and it continued to be detectable 1-3 weeks after the production of antibody to hepatitis B surface antigen. In testing serum from 84 human patients, we found hepatitis B virus DNA in all patients who had hepatitis B surface antigen and hepatitis B e antigen in serum and in 64% of the patients with hepatitis B surface antigen with antibody to hepatitis B e antigen in serum. Also, 3 out of 11 patients who were chronic hepatitis B carriers and who subsequently lost hepatitis B surface antigen were found to test positive for hepatitis B virus in serum. In contrast, all patients who lost hepatitis B surface antigen after acute hepatitis B virus infection or those classified as having non-A, non-B hepatitis tested negative for hepatitis B virus DNA. Thus, the modified PCR technique is a sensitive and rapid method for detecting hepatitis B virus DNA-containing virions in serum.