Cytometry is a general name for a group of biological methods used to measure various parameters of cells. Parameters which can be measured by cytometry are cell size and morphology, cell cycle phase, DNA content, the existence or absence of specific proteins on the cell surface or in the cytoplasm [1]. In flow cytometry, actually the sorting mechanism is pretty similar to inkjet printing, which is based on the physics of droplet formation that Lord Rayleigh observed in 1879.  Rayleigh found that without eternal force applied to the stream, the pattern of droplets is unstable and unpredictable.   Later,  the technology was used in the electrostatic charges in inkjet printer by  Richard Sweet in 1965 [2].  

The first video from youtube introduces the principle of flow cytometry technique and the second video shows some cool images of drops in flight captured by using the JetXpert system.

 

Introduction of Flow Cytometry 

 

Reference:

[1] http://en.wikipedia.org/wiki/Cytometry

[2] http://bitesizebio.com/ Evolution Flow: The Historical Background of Flow Cytometry by Rachael Walker on 28th of January, 2013 in Flow Cytometry

[3] JetXpert