Raman spectroscopy shows great promise to supplement and possibly replace standard histopathological diagnosis. We have demonstrated the ability to discriminate between healthy primary human keratinocytes (black line), primary human keratinocytes infected with the E7 vector of HPV-16, which represents an extremely early stage of neoplastic development (blue line) and finally CasKi cells, an advanced cervical cancer derived cell line (red line). We are currently characterising the Raman spectra of other cancer cell types. One dream is that during surgery, suspect tissue might be immediately diagnosed in situ.

MODULATED RAMAN SPECTROSCOPY

Label-free chemical characterization of single cells is an important aim for biomedical research. Standard Raman spectroscopy provides intrinsic biochemical markers for noninvasive analysis of biological samples but is often hindered by the presence of fluorescence background. We have developed an innovative new modulated Raman spectroscopy technique to filter out the Raman spectra from the fluorescence background. The method is based on the principle that the fluorescence background does not change whereas the Raman scattering is shifted by the periodical modulation of the laser wavelength. Exploiting this physical property and importantly the multichannel lock-in detection of the Raman signal, the modulation technique fulfills the requirements of an effective fluorescence subtraction method. Minimal user intervention is required, making the method online and less time-consuming than the other fluorescent suppression methods. 

Key References

Modulated Raman Spectroscopy for enhanced identification of bladder tumour cells in urine samples, Elisabetta Canetta, Michael Mazilu, Anna Chiara De Luca, Antonia E. Carruthers, Kishan Dholakia, Sam Neilson, Harry Sargeant, Tina Briscoe, C. Simon Herrington, and Andrew C. Riches, accepted for publication in the Journal of Biomedical Optics (2011)

Enhanced bioanalyte detection in waveguide confined Raman spectroscopy using modulation techniques, P.C. Ashok, A.C.D. Luca, M. Mazilu, and K. Dholakia, (article online in advance of print) Journal of Biophotonics (2011)

Waveguide confined Raman spectroscopy for microfluidic interrogation, Praveen C. Ashok, Gajendra P. Singh, Helen A. Rendall, Thomas F. Krauss  and Kishan Dholakia, Lab on a Chip 11(7), 1262 - 1270 (2011).(Also contains a highlight of Kishan Dholakia as a contributor to this special 10th Anniversary UK issue)

Optimal algorithm for fluorescence suppression of modulated Raman spectroscopy, Michael Mazilu, Anna Chiara De Luca, Andrew Riches, C. Simon Herrington, and Kishan Dholakia, Optics Express 18, 11382-11395 (2010)

Near-Infrared Raman Spectroscopy Using Hollow-Core Photonic Bandgap Fibers, K. M. Tan, G. P. Singh, C. S. Herrington, and C. T. A. Brown, Optics Commun. 283(16) 3204-3206 (2010)

Discrimination of normal from pre-malignant cervical tissue by Raman mapping of de-paraffinized histological tissue sections, Khay M. Tan, C. Simon Herrington, Christian T. A. Brown, Journal of Biophotonics (online in advance of print) (2010)

Fiber probe based microfluidic raman spectroscopy, P. C. Ashok, G. P. Singh, K. M. Tan, and K. Dholakia, Optics Express 18(8) 7642-7649 (2010) (Highlighted in optics.org)

On-line fluorescence suppression in modulated Raman spectroscopy, Anna Chiara De Luca, Michael Mazilu, Andrew Riches, Simon C. Herrington, Kishan Dholakia. Analytical Chemistry 82(2) 738-745 (2010) (BBC news article) (Daily Express news article).

• < Prev
• Next >