The IGFBP-3 Colorimetric Cell-Based ELISA Kit provides a lysate-free, convenient, and high-throughput approach for sensitive detection of IGFBP-3 protein expression profile in cells. The kit can be used for measuring the relative amounts of IGFBP-3 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie siRNA or chemicals), or activators have on IGFBP-3.