BrdU / EdU Incorporation Assays 

By identifying cells that are actively going through the S phase of the cell cycle, the incorporation assays for BrdU (bromodeoxyuridine) and EdU (5-ethynyl-2'-deoxyuridine) are commonly used methods to quantify DNA synthesis and cell proliferation. During replication, the thymidine analogs BrdU and EdU are integrated into freshly synthesized DNA. DNA denaturation and anti-BrdU antibody immunostaining are necessary for detection in the BrdU assay. The EdU assay, on the other hand, uses "click chemistry," a copper-catalyzed reaction that preserves cell morphology and permits multiplexing with other markers while enabling quicker and more effective detection without the need for DNA denaturation. These assays offer a potent and quantitative way to evaluate cell proliferation dynamics at single-cell resolution, and they are frequently employed in drug screening, developmental biology, cancer research, and studies of cell cycle regulation.