Subpopulations of cells or particles that have been resolved by fluorescence or physical parameters can be isolated for further experimentation by using the instrument's cell sorting capability.
A piezoelectric quartz crystal connected to the nozzle causes the cell stream to oscillate and form droplets. The droplets are formed at a high enough frequency so that any given droplet will contain only one cell. When a cell meets the criteria defined by sort "windows", the sorting electronics system places a charge on the cell stream at exactly the time when the droplet containing the cell of interest is breaking off from the stream. The droplet passes between two metal plates that have a very high voltage.
The resulting magnetic field forces the charged droplet to be deflected toward the plate with the opposite charge. By placing a collection vessel in the deflected droplet's path, cell populations up to 99% purity can be collected at rates of approximately one thousand per second. The current flow cytometer can sort four populations at the same time.
The BD FACSAria cell sorter is operated by Cytometry Core Facility personnel only. Please contact the Core Facility Manager to discuss your cell sorting needs.