Detection and identification of HBV DNA and DNA subtypes of HBs-antigen by the use of the polymerase chain reaction and non-radioactive probes

Abstract

A technique of nested polymerase chain reaction (PCR) and hybridization with non-radioactive probes was developed for the detection and identification of HBV DNA and HBs-subtypes in very small volumes of human sera. Four oligonucleotide primers (20 mer) complementary to DNA sequences in the S region of HBV and probes (18 or 20 mer) conjugated to alkaline phosphatase were used for the present PCR assay. The results of the PCR assay coincide with those of enzyme immunoassay (EIA) in 14 HBe-positive and 59 HBe-negative samples with 98.6% of specificity. The HBV subtypes adr and adw were identified using an 18-mer DNA probe in 30 samples with an accuracy of 100%. Further, the DNA subtypes were clearly demonstrated in 3 samples where HBs-antigen was undetectable. These results indicate that amplification of HBV DNAs by PCR and their detection with non-radioactive probes is a reliable tool for diagnosis of HBV infection in clinical laboratories.