Purification of anti-DNA antibodies from systemic lupus erythematosus (SLE) serum is usually achieved by DNA-affinity chromatography. However, using DNA-cellulose, the present study has found that this technique results in very low yields of DNA binding activity, much of which is contaminated with DNA simultaneously released during chromatography. In comparison it has been found that the anionic dyes Cibracon blue F3GA and Procion red HE3B, bound to crosslinked agarose, give more than 80% recovery and purification of DNA binding activity from whole SLE serum of 11- and 7-fold respectively. The majority of serum immunoglobulin did not bind to the dyes, but that which did, including anti-DNA antibody, bound by ionic interaction. Dye-ligand chromatography is therefore suggested as a useful technique for high yield recovery of partially purified DNA binding activity which can be subjected to further purification procedures, such as preparative isoelectric focusing.