Flow microfluorometry FACS

Flow microfluorometry (fluorescence activated cell sorting, FACS) 

An instrument developed at the Los Alamos Scientific Laboratory permits analysis of large numbers of single cells with respect to DNA and protein content, cell volume, etc. (Fulwyler, 1965 Kraemer et al., 1973 Klevecz et al., 1975 Herzenberg et al., 1976). The output data from a large population of cells consists of, for example, a distribution of the values of cellular DNA content or cell volume. In addition to the capability for complex analyses the instrument is able to physically separate particular cell subpopulations of interest. 

Cells are stained with fluorescent dyes specific for a particular cell constituent (e.g. ethidium bromide at 0.1 mg/ml stains DNA in 

To give some idea of the results CHO cells pulse labelled with [3H]thymidine were stained with either ethidium bromide or using the acriflavin-Feulgen method (again staining DNA) and submitted to flow microfluorometry and cell sorting. 

The leading edge of the G1 peak of cells was shown by autoradiography to have only 4% of the cells labelled and similarly the trailing edge of the G2 + M population had 19% of the cells labelled. Cells sorted from between the two peaks had 93% labelled. 

---