Matrix metalloproteinases (MMPs) belong to a family of secreted or membrane-associated proteins capable of digesting extracellular matrix components. The importance of MMPs in tumor development and invasion as well as other diseases is well known. The SensoLyte® Generic MMP Assay Kit can be used to detect the activity of a variety of MMPs, including MMP-1, 2, 3, 7, 8, 9, 12, 13, and 14 or for high throughput screening of MMPs’ inducers and inhibitors. The substrate is a thiopeptolide that is cleaved by the MMPs, releasing a sulfhydryl group, which can be detected with a color-developing thiol-reactive agent, 4,4’-dithiodipyridine or Ellman’s Reagent at 412 nm using a microplate reader. The assays are performed in a convenient 96-well microplate format.