Caspase 3, also known as CPP32, Yama or apopain, belongs to the CED-3 subfamily of the caspase family. It is a key enzyme in the process of apoptosis and the most studied caspase in mammalian cells. Caspase 3 exists in the cytoplasm in the form of zymogen under normal condition and has no activity. In the stage of apoptosis, caspase 3 is activated, and the activated caspase 3 consists of two large subunits and two small subunits, which cleaves the corresponding cytoplasmic and nuclear substrates and ultimately leads to apoptosis. This caspase 3/7 activity assay kit is based on caspase 3/7 that can catalyze the substrate Ac-DEVD-pNA to generate yellow pNA (p-Nitroaniline). The pNA has a strong absorption near 405 nm, The activity of caspase 3/7 can be calculated by determining the absorbance at 405 nm.
