Used for quantitative measurement of calpain enzyme activity in rat tissue samples, particularly in research related to muscle degradation, neurodegenerative diseases, and cellular apoptosis. Commonly applied in studies of muscle physiology, such as meat tenderization in post-mortem muscle, and in neuroscience to assess calpain activation linked to brain injury or stroke. Enables high-throughput analysis in experimental models where calpain-mediated proteolysis plays a key role.