The Cyclin D1 Colorimetric Cell-Based ELISA Kit provides a lysate-free, convenient, and high-throughput approach for sensitive detection of CyclinD1 protein expression profile in cells. The kit can be used for measuring the relative amounts of CyclinD1 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie siRNA or chemicals), or activators have on CyclinD1.