Chemiluminescence-based BrdU ELISA to measure DNA synthesis

We describe a simple, sensitive, nonradioactive, relatively rapid and relatively inexpensive protocol to measure DNA synthesis in cultured cells by a chemiluminescent bromodeoxyuridine (BrdU) enzyme-linked immunosorbent assay (ELISA). We show that it exhibits similar sensitivity and activity as traditional 3H-thymidine incorporation assays and a commercial chemiluminescent BrdU ELISA kit when tested in commonly used cell lines, such as NIH 3T3 cells, mink lung epithelial cells (Mv1LU), and baby hamster kidney (BHK-21) fibroblasts. This assay also exhibits a wider dynamic range than colorimetric BrdU ELISA methods. Besides being a viable, nonradioactive alternative to 3H-thymidine incorporation assays, our BrdU ELISA is less expensive than a commercial chemiluminescent BrdU ELISA kit.