Incorporation of deoxynucleotides into DNA by diethylaminoethyldextran-treated lymphocytes

Abstract

In the presence of DEAE-dextran cultured human lymphocytes will utilize deoxynucleotides for the synthesis of DNA, whereas in the absence of DEAE-dextran no incorporation of deoxynucleotides is detected. Labeled deoxynucleoside mono-, di- and triphosphates are incorporated into DNA at approximately the same rate. Deoxynucleotide incorporation is essentially linear for 10 min but continues at a gradually diminishing rate for an additional 20-50 min. The initial rate of DNA synthesis is at least 20-40% of the in vivo rate; in those cells that are in S phase, 0.7-1.5% of the DNA is synthesized. By the 3 properties examined (restriction to S phase, semiconservative mode and initial product in short chains), DNA synthesis in DEAE-dextran-treated cells resembles DNA synthesis in vivo.