Early apoptosis is followed by annexin V staining. Further, detection of caspase-3 activation could be challenging in adult fibroblasts.

Thanks dear professor Divaker.

Thanks Dear Jorn,

please I will use this kit it's OK? 

http://www.abcam.com/annexin-v-fitc-apoptosis-detection-kit-ab14085.html

You will probably want to do more than one assay. Annexin V/PI is pretty standard. If you want to use Caspase 3 cleavage, you need to show that it is necessary for cell death by quantifying cell death in the presence or absence of a Caspase-3 inhibitor. It’s insufficient just to show that procaspase 3 is cleaved to active caspase-3. 

Thanks all.