Inhibition of DNA synthesis after ara-G treatment. Cell cultures of CEM (▪), Raji (▾), and ML-1 (♦) were exposed to various concentrations of ara-G for 3 hours and pulsed with [³H]thymidine. The [³H]DNA levels were measured and expressed as percent of control cells. Data points represent 3 independent experiments conducted in quadruplicate; bars, SE.