Flow Cytometry

Flow cytometry is a process in which physical and/or chemical characteristics of single cells (or other particles) are measured as they pass through a flow cytometer individually in a fluid stream in front of a light source. Measured parameters include light scattering and fluorescence. Multiple parameters can be measured simultaneously and correlated to identify subsets of populations. In addition, qualitative and quantitative changes in these parameters can be used to characterize normal and abnormal cellular function.

The acronym FACS stands for “fluorescence-activated cell sorter”. A cell (or flow) sorter is a flow cytometer that has the additional capability of isolating cells (or particles) that satisfy certain user-defined criteria. Cells sorted by flow cytometry are routinely used for functional assays, cloning of gene-modified cells, genome-wide expression studies, or proteomic analyses.

Significant improvements in instrumentation, lasers, fluorochromes/fluorescent proteins/quantum dots, and analysis software have all contributed to the recent rapid expansion of flow cytometric applications.