[Use of immobilized ethidium bromide for the isolation and fractionation of DNA from solutions, biological fluids and cell lysates].

Possible use of ethidium bromide immobilized on polyacrylamide gel for DNA extraction from biological media, e.g., cell lysates and blood serum, is discussed.

[Fluorometric determination of radiation damages to leukocyte DNA by Birnboim and Jevcak's method].

Fluorometric measurements of the levels of radiation injury to DNA of leucocyte lysates were made on the basis of the estimates of alkaline denaturation rate obtained by the method of Birnboim and Jevcak. Leucocytes of human blood in vitro and rats were exposed to doses of 0.5, 1, 1.

[Effect of alkylating derivatives of cyclic adenosine-3' ,5'-monophosphate on proliferation of mouse bone marrow stem cells].

The effect of the physiological concentration of cyclic adenosine-3' ,5'-monophosphate (cAMP) analogues on the proliferation of mouse bone marrow stem hemopoietic cells (CFUs) was examined. The stimulating effect was estimated from the decrease in CFUs expressed in the percentage derived from comparing the number of spleen colonies in the control and experimental groups treated with hydroxyurea 10(-3) M (incubation with hydroxyurea resuted in the cell death in S-phase). Cyclic AMP stimulted the proliferation of CFUs by 60%, while its analogues such as 8-(N-chloroacetylaminoethylamino)-cAMP, 1-(N-chloroacetylaminoethyoxy)-cAMP and 1-(N-(p-fluorosulfonyl)-benzoylaminoethoxy)-cAMP stimulated the proliferation by 39.