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. MMP-3 (stromelysin-1, transin-1) is proposed as a potential therapeutic target. The SensoLyteŽ 490 MMP-3 Assay Kit is a complete assay system designed to continuously analyze MMP activities or to screen MMP-3 inhibitors using a fluorogenic MMP-3 substrate. The assays are performed in a convenient 96-well or 384-well microplate format. The kit provides speed, convenience and accuracy in analyzing MMP-3 activities and screening MMP-3 inhibitors.