Unlike most cell-based thymidine analogassay kits that can only measure qualitative differences in incorporation, the CytoSelect™ IdU Competitive ELISA Kit quantifies IdU incorporated into cellular DNA. The unknown DNA samples or standards are first added to a microplate preadsorbed with a IdU conjugate. After a brief incubation an anti-IdU monoclonal antibody is added, followed by an HRP-conjugated secondary antibody. The IdU in solution and the IdU coated on the plate compete for binding of the antibody. If no IdU is in solution, all of the antibody will bind to the plate resulting in a high signal. High levels of IdU in solution will bind the antibody and be washed away, resulting in a low signal.
Assay Principle for the CytoSelect™ BrdU Cell Proliferation ELISA Kit.
Serum Stimulation of Proliferation in HEK 293 Cells. Cells were plated overnight at 37ºC. Cells were then incubated in the presence or absence of 10% FBS for 24 hours, followed by treatment with 10 µM BrdU for 1 or 3 hours. Cells were tested for BrdU incorporation according to the assay protocol.