Fig. 1.

Fluorescent signals in PHA-stimulated lymphocytes at interphase following one-color FISH with the AML1 probe. a Cell with one singlet and one doublet (SD cell), which is an S-phase cell in which one allele has replicated while its partner has still to do so; b cell with two singlets (SS cell), in which neither allele has replicated; and c cell with two doublets (DD cell), in which both alleles have replicated