[The primary interaction with DNA of "latent high-avidity antibodies" from gamma-globulin preparations, probably, is determined by the presence of a cofactor].

Highly positive by Farr assay, native DNA-binding fraction was derived from commercial normal human gammaglobulin preparations by ion-exchange chromatography. Human serum immunoglobulins of any isotype were not involved into this binding. The existence of nonimmunoglobulin factor primarily binding native DNA and intermediating DNA-Ig interaction is assumed.