Specificity analysis of antibodies to single-stranded micrococcal DNA in the sera of normal human subjects and patients with systemic lupus erythematosus.

To evaluate the properties of antibodies to bacterial DNA in the sera of normal human subjects (NHS) and patients with systemic lupus erythematosus (SLE), the effects of ionic strength and pH on their binding to single-stranded DNA (ssDNA) from Micrococcus lysodeikticus (MC) were measured. By ELISA, antibodies to MC ssDNA in NHS showed greater activity at high ionic strength (0.2-1.0 M) than antibodies in lupussera. Similarly, antibodies in NHS had higher activity at pH 9 than lupus anti-DNA