situ zymography: a molecular pathology technique to localize endogenous protease activity in tissue sections. Vet Pathol

Abstract. Proteases play important roles in modulating a wide range of cellular functions, in the reg-ulation of biologic processes, and in the pathogenesis of various diseases. Several molecular techniques are available to identify and characterize proteases in cells and tissues. Most of these techniques do not provide information on the activity of proteases in tissues. In situ zymography (ISZ) is a relatively low-cost technique that uses specific protease substrates to detect and localize specific protease activities in tissue sections. Used in combination with other techniques, ISZ provides data that further our understanding of the role of specific proteases in various pathologic and physiologic conditions. This review describes the general principle of ISZ and highlights the past and future applications of this technique in molecular pathology. Key words: Collagenase; gelatinase; in situ zymography; matrix metalloproteinases; protease. Proteases are enzymes that cleave proteins by the catalysis of peptide bond hydrolysis. On the basis of their catalytic mechanism, proteases are further di-vided into five catalytic classes: aspartic, cysteine, metalloproteinase, serine, and unclassified.1 Ther