What are Flow Cytometry and Cell Sorting Techniques?

Flow Cytometry is a means of measuring certain chemical and physical characteristics of cells or particles as they travel in suspension one by one past a sensing point. Flow cytometry combines the techniques of optical and fluorescent detection and is a standard method of automated rapid cell analysis

Typically fluorescent probes are bound to particular cell associated molecules to determine biochemical and molecular characteristics of cells. These probes are excited by the laser beam and the emitted light is detected and converted. Any cell component or function that can be detected by a fluorescent compound conjugated to a cell can be examined. Physical characteristics such as cell size, shape and internal complexity can also be measured as these characteristics affect the way light is scattered as they travel past the laser beam.

Cell Sorting utilises the detection and characterisation methods of flow cytometry to separate mixtures of cells. The basis of sorting is divided into 3 steps

Detection – Particles are detected and characterised through laser stimulated light scatter and fluorescence.
Charging – An electrostatic charge is passed through the fluid surrounding the particles
Defection – The selected particles are electronically deflected into separate collection tubes, depending on their different electrostatic charge.

Cell sorting by flow cytometry results in high purity yields because multiple parameters can be assessed simultaneously at a rapid rate.