Stewart Smith: Label free cell sorting
From Billy Rosendale on October 4th, 2016
In this video Stewart describes his research on people’s experience
of everyday landscapes and how access to different outdoor environments,
and barriers to access, impact on health and quality of life.
Much of the microsystems research within the Institute for Integrated Micro and Nano Systems (IMNS) is focused on applications in biology and biomedicine. This ranges from work on biosensors using electrochemistry, drug delivery systems designed for implantation into the human body, and digital microfluidics for droplet manipulation and lab on a chip applications.
In recent years, a new bioelectronics research group has begun to investigate the application of a technique called Dielectrophoresis (DEP) in cell biology. DEP uses electrical fields, applied using microfabricated electrodes, to manipulate polarizable particles suspended in solution. If the particles are biological cells, for example stem cells used in regenerative medicine, then it is possible to characterise and manipulate them based on their dielectric properties. This can reveal useful information about the cells but can also enable cell sorting by selectively capturing and holding cells using electric fields. By varying the frequency of the applied electric field, different cells are either attracted or repelled from the surface of the electrode chip. DEP sorting is more gentle than many standard cell sorting technologies such as FACS (fluorescence activated cell sorting) and does not require labelling with fluorescent dyes. This is very attractive for the preparation of cells for clinical treatment where it is essential to sort out the desired cells from a heterogenous population in order to eliminate possible risks, and where contamination of the cells with fluorescent labels is undesirable.
Sorting has been demonstrated with human embryonic stem cells where it is possible to discriminate between pluripotent cells, differentiated cells and the feeder cells they are grown on. Another area of investigation using DEP is in the application of very high frequency signals, which can “reach into” cells and characterise them based on internal properties such as the size of the nucleus. This is at a relatively early stage but has already revealed interesting results, which should be published, in the next year.
We are interested in developing new applications for these techniques beyond what has already been done. If you would like to discuss using DEP or other microfluidic and microsystems technologies in your research then please get in touch.
Find out more:Dr Stewart Smith, School of Engineering profile: http://www.eng.ed.ac.uk/about/people/dr-stewart-smith
Edinburgh Research Explorer: http://www.research.ed.ac.uk/portal/ssmith13