Accumulation and elimination of intracellular ara-GTP in 3 leukemia cell lines. Exponentially growing cultures of CEM (▪), Raji (▾), and ML-1 (♦) were incubated either with the indicated concentration of ara-G for 3 hours (A), or with 100 μM ara-G for up to 12 hours (B), or with 100 μM ara-G for 3 hours, washed, and incubated in drug-free medium (C). The extracted nucleotides were analyzed by HPLC. Data points represent mean of at least 3 independent experiments conducted in duplicate (A-B) or mean of 5 independent experiments (C).