Detection of markers of hepatitis B infection in serum dried on to filter-paper: an application to field studies.

In an attempt to find a cheap, reliable, and convenient method for the transportation and storage of serum specimens during seroepidemiological surveys, a technique in which serum was dried on to pieces of filter paper was developed and evaluated. For the evaluation, a total of 382 sera were selected from the extensive serum collection held by the WHO Collaborating Centre for Virus Reference and Research at Fairfield Hospital, Australia. These sera were dried on to pieces of filter-paper, stored at different temperatures and then tested for the presence of the various markers of infection with hepatitis B virus by solid-phase radioimmunoassay. The results were in complete agreement with those obtained on whole serum specimens. In addition, storage at 4 degrees C, room temperature (22 degrees C), or 37 degrees C for up to 30 days did not alter the sensitivity of the test. This technique may be useful in field surveys, not only for the detection of hepatitis B infection, but also in the study of other diseases and metabolic disorders.