Isolation of single microorganisms using micromanipulation technology

Currently the main approaches used for direct isolation of single cells put high demands on the skill of the operator and are either highly labour intensive (e.g. use of micropipette) or expensive (FACS/Cell sorter). There is strong need for automated, relatively inexpensive technology for the high throughput isolation of micro-organisms that is compatible with new approaches such as microfluidics and microbioreactors.

We will develop an automated system for the isolation of single cells using micromanipulation technology. The systems will be based on

a) Laser tweezers (Paterson), using high intensity gradient, near infrared laser beams to trap and manipulate cells. Single beam gradient force optical traps are a well established technique used to pick up and move microscopic objects, but has limitations, such as relying on the trapping optics being co-linear with the imaging optics and the reliance on high numerical aperture microscope objectives. We will develop optical trapping techniques in order to manipulate single microbes and make use of various emerging trapping technologies developed at Heriot Watt University such as the use of novel multi core optical fibres, ultrafast laser inscription and chemical etching to make devices with three dimensional microfluidic structures and optical waveguide traps to enable a wide range of experiments.

b) Electrokinetic devices (Markx), using non-uniform electric fields to trap and manipulate cells. In particular, systems will be developed in which individual microbes in a stream through a microchannel will be diverted. Current technology often operates at low conductivities, but a concerted effort will be made to develop devices that can work at higher conductivities.

c) Optoelectronic devices, combining electrokinetic effects (e.g. dielectrophoresis) with moving optical fields to define the electric field distribution and particle movement in time.


Please contact Dr Lynn Paterson [Email Address Removed] for information about the optical manipulation (laser tweezers) project and/or Prof Gerard Markx [Email Address Removed] for further information on electrokinetic manipulation.