Nonradioactive techniques have been used for the direct detection of hepatitis B virus DNA in human serum samples. A comparison of two different systems using digoxigenin-labeled DNA probes is presented. Furthermore, oligonucleotides containing one molecule of the hapten digoxigenin at the 5′-end were prepared and used as primers for the polymerase chain reaction. Amplified DNA can be directly analyzed with anti-digoxigenin Fab fragments labeled with alkaline phosphatase and chemiluminescent substrates. © 1992 Academic Press, Inc.