The Chk1 (Phospho-Ser280) Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can monitor Chk1 (Phospho-Ser280) protein expression profile in cells. The kit can be used for measuring the relative amounts of Chk1 (Phospho-Ser280) in cultured cells as well as screening for the effects that various treatments, inhibitors (ie. siRNA or chemicals), or activators have on Chk1 (Phospho-Ser280). Range: > 5000 Cells. Sensitivity: >5000 cells