PhD at the University of Edinburgh (start date October 2010, UK students only)

“CARS microscopy of biological samples” with Dr Andy Downes

 

Microscopy of biological samples is of limited use when white light is used. So biologists use fluorescent dyes – which are either added to cells, or they are produced by genes which have been inserted into the DNA. These fluorescently-labelled images, although useful, are limited in their application. Raman spectroscopy is a label-free technique which is similar to infra-red spectroscopy, which excites molecular vibrations. These vibrations occur at different frequencies in different molecules – for example DNA, proteins and lipids. However, Raman spectroscopy is too slow to image live cells.

 

Coherent anti-Stokes Raman Scattering (CARS) microscopy is around 5 orders of magnitude quicker than normal Raman, so images of live cells can be acquired in a matter of seconds. Very few of these microscopes exist worldwide, and we have one of the best here in Edinburgh.

 

  

 

Left: 212 μm square region of a 20 μm thick sample of cancerous breast tissue. (A) Differential interference contrast (DIC), (B) CARS tuned to 1662 cm-1 (proteins), (C) two-photon fluorescence (2PEF), (D) second harmonic generation (SHG), (E) sum frequency generation (SFG). Centre: 2PEF image of anti-cancer drugs in live breast cancer cells – green channel shows the accumulation of Doxorubicin molecules within the nuclei. Right: CARS image of 1 μm diameter latex spheres digested by (and contained within) a human macrophage cell, 50 x 35 μm. Blue maps the CARS signal specific to latex (3054 cm-1). All images were acquired in 21 seconds.

 

PhD research programme

 

The successful candidate will:

 

  • Optimize the speed and sensitivity of CARS imaging, to enable monitoring of lower concentrations of biomolecules

 

  • Choose a biomedical research area with one of our many collaborators (e.g. monitoring stem cell differentiation, cancer diagnosis, cancer drug resistance, neurodegenerative disease formation) or develop your own application

 

 

  • Acquire CARS images and complementary images of live cells or tissue

 

We have an extensive suite of biological laboratories, connected to our CARS microscope and Raman spectrometer rooms.

 

Informal Enquiries to Dr Andy Downes (tel: 0131 651 7072, e-mail: andy.downes@ed.ac.uk)

 

Closing date: 31 March 2010. Stipend 2010/11 £13650 tax free. UK students only. Applicants require at least a 2:1 degree (masters preferred). Cell biology or knowledge of optics preferred.

 

Funding is subject to approval by the School of Engineering. Click here for Employer Profile.