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.

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, gene expression studies, cloning of gene-modified cells, or proteomic analyses.

Innovations in instrumentation, development of small lasers, discovery of new fluorochromes/fluorescent proteins, and implementation of novel methodologies have all contributed to the recent rapid expansion of flow cytometric applications.