Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful., but often misinterpreted, tool. yielding information on potential. hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tissue sections with in situ zymography. In vivo zymography can pinpoint proteolytic activity to sites in an intact organism. Future development of novel. substrate probes and improvement in detection and imaging methods will increase the applicability of zymography for (reverse) degradomics studies. ; European Union (grant numbers FP7/2007-2013; 263307); Geconcerteerde OnderzoeksActies (grant numbers BOA 2012 017; BOA 2013 014); Fund for Scientific Research of Flanders (FWO-Vlaanderen); University of Leuven Research Fund ; Biochemical Research Methods