Used in molecular biology for labeling and tracking DNA synthesis in cells. It acts as a nucleoside analog that incorporates into newly synthesized DNA during replication, allowing detection through click chemistry with fluorescent dyes or other tags. Commonly applied in cell proliferation studies, cancer research, and developmental biology to visualize active DNA synthesis in vitro and in vivo. Its selectivity for replicating DNA makes it a valuable tool for identifying dividing cells without affecting overall cell function significantly.