Adriamycin-specific fluorescence appears slowly in living [CCRF-CEM human leukemia] cells and is localized in nuclei and chromosomes. N-Trifluoroacetyladriamycin-14-valerate, a recently synthesized adriamycin analog, differs from the parent anthracycline in the rapid appearance of its fluorescence in the cytoplasm of living cells and the lack of any fluorescent binding to nuclei and chromosomes.