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