Zymography is a laboratory technique used to study the activity of enzymes, particularly proteases and glycosidases, in biological samples. It involves the separation of enzymatic proteins by gel electrophoresis under non-denaturing conditions, followed by their renaturation and incubation with specific substrates that mimic natural substrates. The resulting enzymatic activity leads to the degradation of the substrate within the gel, producing clear bands or zones of decreased staining that indicate the presence of active enzymes. There are several variants of zymography, including gelatin zymography, casein zymography, and substrate-specific zymography, each tailored to detect specific enzyme activities. Gelatin zymography, for example, is commonly used to detect protease activity against gelatin, while casein zymography employs casein as the substrate for a broader range of proteases. Zymography can be applied in various fields, including basic research, clinical diagnostics, and drug development. It provides valuable insights into enzyme function, substrate specificity, and regulation, and can serve as a biomarker for diseases associated with dysregulated enzyme activities. Overall, zymography is a versatile and widely used technique that offers qualitative information about enzyme activities and their role in biological processes. It contributes to our understanding of enzyme function and has potential applications in both research and clinical settings.