Analysis of cell proliferation and cell survival by continuous BrdU labeling and multivariate flow cytometry

Halogenated deoxyuridines such as BrdU incorporated into DNA in place of thymidine can be detected by virtue of their ability to quench the fluorescence of Hoechst dyes. This property is the basis for a simple and reliable method of enumerating cells which have incorporated BrdU. Counterstaining with another suitable DNA dye permits resolution of cells in G1, S, and G2 phases of three consecutive cell cycles. In addition to this basic technique, the authors present newer protocols for proliferative analysis of GFP-expressing or cell surface antigen expressing cells versus nonexpressing cells in culture as well as one to determine the absolute number of proliferating and nonproliferating cells by calibration for the volume analyzed. With this technique the proliferative survival of cells can be determined.