The PGP9.5 Colorimetric Cell-Based ELISA Kit provides a lysate-free, convenient, and high-throughput approach for sensitive detection of PGP9.5 protein expression profile in cells. The kit can be used for measuring the relative amounts of PGP9.5 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie siRNA or chemicals), or activators have on PGP9.5.