light microscopy of 13 day-old colonies previously treated for 24 hours with 0.01 microgram/ml , 0.1 microgram/ml , and 1 microgram/ml act d revealed a decrease in colony size and organization , an increase in pyknotic nuclei , and an accumulation of cell debris concomitant with an increase in act d concentration .
C0007610
nuclei
C0007634
cell