Quantification of attached cells in microtiter plates based on Coomassie brilliant blue G-250 staining of total cellular protein.

A method has been developed to determine the relative or actual number of attached cells in microtiter plate wells without making direct cell counts. The procedure is based upon staining total cellular protein with Coomassie brilliant blue G-250, followed by measurement of absorbance at 630 nm in a spectrophotometer designed to read each well of a 96-well microtiter plate. No destaining of cells is required. A linear correlation exists (r = 0.970) between cell number and absorbance over a useful range. Intraplate well-to-well variation is acceptable (CV = 0.101). This method was used to measure the proliferative response of human vascular smooth muscle cells to human serum. It should be useful in other assays involving proliferation of attached cultured cells.