Conversion of dCTP to CTP by isolated nuclei of Ehrlich ascites tumor cells

Isolated nuclei of Ehrlich ascites tumor cells synthesize DNA in vitro using endogenous template and enzymes. Deoxycytidine nucleoside triphosphate (dCTP) is incorporated into acid-insoluble material to a much greater extent than the other substrates, even in the absence of the other triphosphates. Much of the [³H] dCTP is converted to [³H]CTP, some of which is incorporated into RNA, as evidenced by alkali-lability and density on cesium sulfate gradients.