Editing Flow cytometry (section)

=== Cell proliferation assay ===
Cell proliferation is the major function in the immune system. Often it is required to analyse the proliferative nature of the cells in order to make some conclusions. One such assay to determine the cell proliferation is the tracking dye carboxyfluorescein diacetate succinimidyl ester (CFSE). It helps to monitor proliferative cells. This assay gives quantitative as well as qualitative data during time-series experiments.<ref name="pmid17853861">{{cite journal | vauthors = Hawkins ED, Hommel M, Turner ML, Battye FL, Markham JF, Hodgkin PD | title = Measuring lymphocyte proliferation, survival and differentiation using CFSE time-series data | journal = Nature Protocols | volume = 2 | issue = 9 | pages = 2057–67 | year = 2007 | pmid = 17853861 | doi = 10.1038/nprot.2007.297 | s2cid = 13550456 }}</ref> This dye binds covalently with the long-lived molecules present inside the cell. When the cells divide, the molecules divide too and, the daughter cells possess half the dye than the parent population. This decrease in the intensity can be visualized by flow cytometry.<ref name="pmid20972413">{{cite journal | vauthors = Quah BJ, Parish CR | title = The use of carboxyfluorescein diacetate succinimidyl ester (CFSE) to monitor lymphocyte proliferation | journal = Journal of Visualized Experiments | issue = 44 | date = October 2010 | pmid = 20972413 | pmc = 3185625 | doi = 10.3791/2259 }}</ref> In literature, this powerful technique of flow cytometry and CFSE has been used to find the efficiency of T-cells in killing the target cells in cancer such as leukemia. In order to visualize the target cell death, both rapid and slow, scientists have used CFSE labelling with antibody staining of certain kinds of cells and fluorescently labelled microbeads. This also gave information regarding the proliferation of the target cells upon the treatment of certain cytokines.<ref>{{cite journal | vauthors = Jedema I, van der Werff NM, Barge RM, Willemze R, Falkenburg JH | title = New CFSE-based assay to determine susceptibility to lysis by cytotoxic T cells of leukemic precursor cells within a heterogeneous target cell population | journal = Blood | volume = 103 | issue = 7 | pages = 2677–82 | date = April 2004 | pmid = 14630824 | doi = 10.1182/blood-2003-06-2070 | s2cid = 1984056 | doi-access = free }}</ref>