Presence in serum of anti-double-stranded deoxyribonucleic acid antibodies (anti-dsDNA) is one of the diagnostic criteria for systemic lupus erythematosus. Anti-single stranded DNA antibodies (anti-ssDNA) also occur, but their clinical significance is unclear.

The resulting single-stranded DNA (ssDNA) is bound by multiple RecA proteins that facilitate the "strand invasion" process, in which one strand of a nearby homologous double-stranded DNA is displaced by the RecA-associated ssDNA. In older literature, this conversion from exonuclease to helicase activity is referred to as "civilizing".

anti-single stranded DNA antibody (anti-ssDNA) was positive not only in AIH and PBC, but also in those with non-autoimmune-types of chronic liver disease.