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Hi Allan,
 
As Ammasi Periasamy points out, the group of Sunney Xie at Harvard has developed coherent anti-Stokes Raman scattering (CARS) microscopy as a great tool for biological applications. Many papers from the Xie group and other groups (Ji-Xin Cheng, Eric Potma, and others) show the feasibility of CARS for cellular imaging.
 
Instead of nonlinear CARS microscopy, our group is focussing on linear nonresonant and resonant Raman microscopy at high spatial resolution on single cells. Compared to CARS, spontaneous confocal Raman microscopy is easier to implement and has better spectral resolution and a larger spectral bandwidth. This is advantageous in cases where one is dealing with subtle spectral changes in Raman data sets of cells.
 
We have shown that interesting cellular biology can be done with spontaneous confocal Raman microscopy, as the following examples demonstrate:
1) Apoptosis (Uzunbajakava et al., Biophys. J. 84: 3968 (2003))
2) Cytochrome visualization and detection of cytochrome activity in living cells (Van Manen et al., J. Am. Chem. Soc. 125: 12112 (2003); Van Manen et al., Antioxid. Redox Signal. 8: 1509 (2006))
3) Lipid droplet association with phagosomes (Van Manen et al., Proc. Natl. Acad. Sci. USA 102: 10159 (2005))
 
In addition, we have recently been able to combine spontaneous Raman microscopy with fluorescence microscopy on cells by spectrally separating the two signals through the use of fluorescent quantum dots with a large Stokes' shift: Van Manen and Otto, Nano Lett. 2007, DOI: 10.1021/nl0705945 <http://dx.doi.org/10.1021/nl0705945> 
 
Please contact me offline if you are interested in getting pdf's of these articles. More information can also be found at my website "Raman microscopy for cell biology" at http://bpe.tnw.utwente.nl/people/postdocs/PFHenkjan/Henk-Jan%20BPE%20website%20home.doc/
 
While SERS is now indeed being developed for cellular applications by a number of groups and seems to have a bright future in this field, the above examples clearly show that spontaneous Raman microscopy is perfectly capable of multiplexed cellular imaging at high spatial and spectral resolution!
 
Best regards,
 
Henk-Jan van Manen
Postdoctoral fellow
Biophysical Engineering Group
University of Twente, The Netherlands
E-mail: [log in to unmask]

________________________________

Van: Confocal Microscopy List namens Allan Kachelmeier
Verzonden: vr 6/8/2007 8:38
Aan: [log in to unmask]
Onderwerp: Re: Raman confocal


Search the CONFOCAL archive at http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal 
Hi,
 
Has Raman confocal been developed for drug investigations in live or fixed cells? Or is it only realistic to consider surface enhanced Raman? Does anyone use this technology to do biology? Thanks.
 
Allan Kachelmeier
Manager, confocal microscopy core
Oregon Hearing Research Center
OHSU