Stimulation of oligodeoxyribonucleotide synthesis by cytoplasmic factors in the isolated nuclei of leukemic cells.

Nuclei were isolated by hypotonie shock and homogenization from freshly drawn, nonstimulated leukemic leukocytes and were pulse labeled with deoxythymidine triphosphate-3H. Labeled oligodeoxyribonucleotides were separated from the bulk of DNA and proteins by membrane cone filtration and were further purified by alkaline hy drolysis and diethylaminoethyl cellulose chromatography. In parallel experiments, cytoplasmic factors, obtained after removal of nonsoluble material from the cytoplasm by high-speed centrifugation, were included. More than a twofold increase of label incorporation into oligodeoxy ribonucleotides was observed.