Molecular approaches for production of B19 antigen.

Owing to the lack of a practical means of production of large quantities of virus in cell culture, present tests to screen for parvovirus antibody rely on the use of virus obtained from the sera of blood donors during the brief, intensely viraemic phase of acute infection (Cohen et al, 1983). Accordingly, antigen is scarce and testing for parvovirus antibody is confined to a few centres. Availability of recombinant antigen would make the test more widely available, and by circumventing the requirement for use of whole virus render the test safer (Cohen et al, 1988). Therefore, constructs of parvovirus DNA encompassing the region of the genome coding for the structural proteins in expression vectors with T7 or trc or tac promoters were made, and proteins produced by the resulting clones tested for their ability to react with B19 antibodies from human sera. Additionally, recombinant B19 DNA was used as a hybridization probe for virus in clinical specimens, and a sensitive polymerase chain reaction assay was investigated as a tool for parvovirus diagnosis.