No DNA fragmentation is detected in MKs with a localized activation of caspase-3.

A double staining between the anti–caspase-3a Ab (red) and the TUNEL technique (green) was performed. The nucleus was labeled with DAPI. Panels A-C: an apoptotic MK that exhibited a condensed chromatin (B) is stained in green by the TUNEL technique (C). This MK has a diffuse and strong labeling by the anti–caspase-3a Ab (A). In panels D- F, a maturing MK is illustrated. Chromatin does not show signs of condensation (E). No DNA fragmentation is detectable by the TUNEL technique (F). However, a granular pattern of labeling by the anti–caspase-3a Ab is observed (D). Original magnification, × 630.