Fig. 1. Growth and morphological characteristics of PMA-resistant clones.
A, growth curves of wild-type K562 cells and the EMS
mutagenized clones, C1 and C4, in the presence (, , and ) or
absence (, , and ) of PMA (40 nM). The growth rate
of the cultured cells was determined as described in "Materials and
Methods." B, wild-type K562 or C1 and C4 clones were
treated with or without PMA (40 nM) for 4 days, affixed to
the slide by cytospin, and stained using the May-Grunwald procedure as
described in "Materials and Methods." The cells were analyzed and
photographed at x100 under light microscopy.