Used extensively in biochemical research to measure caspase-3 enzyme activity, which is crucial for studying apoptosis (programmed cell death). It serves as a substrate that, when cleaved by caspase-3, releases p-nitroaniline (pNA), producing a detectable color change. This allows researchers to quantify apoptosis in cell cultures and tissues, aiding in the study of cancer, neurodegenerative diseases, and other conditions involving abnormal cell death. It is also employed in drug development to screen compounds that modulate caspase-3 activity, providing insights into potential therapeutic agents.