To evaluate further bacterial DNA immunization as a model to study antigen drive in the anti-DNA response, the specificity of induced monoclonal anti-DNA antibodies was characterized. A panel of IgM and IgG monoclonal anti-DNA antibodies was produced from spleen cells of BALB/c mice immunized with single-stranded DNA from E. coli complexed to methylated bovine serum albumin in complete Freund's adjuvant. The binding of these antibodies to DNA and non-DNA antigens was tested by ELISA to assess their range of polyspecificity. These monoclonal antibodies were found to bind to nucleic acid as well as non-nucleic acid antigens, such as beta-galactosidase, cardiolipin, Ro, La and Sm. These studies demonstrate that anti-DNA antibodies from normal mice, although induced by bacterial DNA, may display a broad range of antigen recognition and thus resemble lupus anti-DNA antibodies, many of which are polyspecific, in their pattern of cross-reactivity.