ABSTRACT
Cell proliferation or cell division plays a crucial role in tissue and cellular homeostasis for proper growth, development, and maintenance of an organism. Since the DNA has to replicate prior to cell division, the rate of DNA synthesis reflects cell replication. As DNA synthesis is a critical phase involved in cell proliferation, the quantification of DNA synthesis provides very supportive evidence for judging cell multiplication. Tritiated thymidine is the most widely used radiotracer for imaging tumor proliferation. The synthetic pyrimidine analog of thymidine, 5-bromo-2'-deoxy-uridine (BrdU) can be employed as a substitute for thymidine and can be integrated into cellular DNA during the synthesis phase of the cell cycle to study proliferation of a given cell population. Metabolic activity of a particular cell population can be employed to measure the rate of cell proliferation. The reduction of tetrazolium salts or Alamar blue by metabolically active cells can also be used as markers for measuring cell proliferation.
