Comparison of daunorubicin and Lysosensor yellow/blue DND-160 distribution in U-937 cells. Parental U-937 cells (A and B) and U-A10 cells (C and D) were exposed to 500 ng/mL of daunorubicin for 1 hour, and the cells were washed, visualized by fluorescence microscopy, and photographed. Parental U-937 cells (E and F ) and U-A10 cells (G and H) were exposed to Lysosensor yellow/blue DND-160 (10 μmol/L) for 2 hours, and the cells were washed, visualized by fluorescence microscopy, and photographed. Shown are photographs of typical single cells centered within the frame such that the perimeter of the cell approximately reaches the edge of the photograph.