[Factors affecting the DNA-binding activity of the blood serum in in patients and healthy persons at low ionic strength].

Interaction of blood serum proteins with native DNA at low ionic strength [0.05 M NaCl and 0.015 M sodium citrate], estimated by adsorption of DNA-protein complex on nitrocellulose filtrs, depended on specific activity, molecular weight of DNA as well as on the amount of DNA and blood serum in the samples. DNA-binding activity of blood serum from the patients should be estimated at such ratio of components, when the blood serum from healthy persons adsorbed minimal quantities of DNA, since the molecular weight and specific activity of the DNA preparations might vary in various samples. As a factor, regulating the rate of DNA binding on filtrs, such amount of blood serum from patients should be added to the samples, which corresponded to the maximal amount of normal blood serum causing no binding with the DNA preparations.