Table 1.

H₂O₂ leukemic primitive cell clonogenic capacity

	Unstimulated	5 μM H2O2
BM	68 ± 2	86 ± 7*
UCB	45 ± 4	12 ± 2*
HL-60	310 ± 4	0*

A methylcellulose clonal assay was used to quantify clonogenic capacity of primitive cells obtained from BM, UCB and HL-60 lineage. Clonogenic capacity of BM was increased, showing that H₂O₂ induced the improvement of the capability of these cells to generate their progeny. UCB colonies decreased around 70% while HL-60 stimulated with H₂O₂ was not able to generate clones. The data are expressed as the mean ± SEM of 4 experiments. *P< 0.05, ANOVA.