There are several kinds of cell proliferation assays to determine cell proliferation, which could be used as a prognostic and diagnostic tool in certain cancers. Most of these assays are based on the quantification of DNA levels or synthesis, cellular metabolism or proliferation-specific proteins to assess the extent of cell proliferation. DNA synthesis is a very popular and widely used method to study cell proliferation.
DNA synthesis is accompanied with cell proliferation and the measurement of DNA-synthesizing cell is essentially synonymous with the measurement of cell proliferation. The direct measurement of new DNA synthesis generally involves the incorporation of a labeled nucleoside into genomic DNA and the labeled nucleoside can be detected with a reporter. Thymidine analogs can be used to be incorporated into DNA, substituting thymidine during DNA replication and labeling the newly synthesized DNA. Based on this principle, several kinds of technique are developed for the quantification of cell proliferation through the measurement of newly synthesized DNA including BrdU, EdU and IdU methods. The labeled proliferating cells can be detected by several methods including immunohistochemistry (IHC), immunocytochemistry (ICC), flow cytometry and so on. There are also some specific antibodies which could be used for the identification of labeled compounds such as BrdU to quantify cell proliferation with immunoperoxidase, immunofluorescence or avidin-biotin complexs. This method makes it possible to assess cell proliferation with microscopic detection at cellular level and routine screening. It is a reliable and reproducible method for the study of cell proliferation.
Figure 1. The experimental results of Cell Proliferation Assay By DNA Synthesis
To evaluate cell proliferation through quantification of newly synthesized DNA has many advantages including accuracy and high reliability. This method allows the microscope-based image analysis for selectively measuring DNA contents and high resolution data which enables the high throughput analysis of the results.