Fig. 3.

FACS analysis of uptake of NST-732 by Jurkat cells undergoing apoptosis induced by anti-Fas Ab. A. Control cells (solid line) versus apoptotic cells (dashed line). Analysis of 10⁴ cells after incubation with NST-732 (50 µM). Apoptosis was associated with a shift of the cell population to a new and distinct peak of higher fluorescence, reflecting enhanced uptake of NST-732 upon induction of apoptosis. B, C. Co-staining of NST-732 versus propidium iodide (PI); control cells (B) versus apoptotic cells (C). As shown, most of the cells undergoing apoptosis induced by anti-Fas Ab were in the early stages of the process (EAC), manifesting enhanced uptake of NST-732, while excluding PI (right lower quadrant). This shows the capability of NST-732 to perform selective uptake into apoptotic cells at an early stage, wherein membrane integrity is still maintained. In addition, NST-732 also detected the cells in the late stages of the apoptotic process, manifesting uptake of both NST-732 and PI. The figure describes a representative experiment out of ten performed