Raman spectral imaging of single living cancer cells: a preliminary study.
Raman microspectroscopy allows probing subcellular compartments and provides a unique spectral fingerprint indicative of endogenous molecular composition. Although several spectroscopic cell studies have been reported on fixed samples, only few attempts concern single growing cells. Here, we have tested different optical substrates that would best preserve cell integrity and allow direct measurement of Raman spectra at the single living cell level. Calu-1 lung cancer cells were used as a model and their morphology and growth were assessed on Raman substrates like quartz, calcium fluoride, and zinc selenide. Data show that quartz was the most appropriate taking into consideration both cell morphology and proliferation rate (47% on quartz vs. 55% of BrdU-positive cells on conventional plastic). Using quartz, 40 cells were analysed and Raman spectra were collected from nuclei and cytoplasms using a 785 nm laser excitation of 30 mW at the sample, in the spectral range of 580-1750 cm(-1), and an acquisition time of 2 x 10 sec/spectrum. Discriminant spectral information related to nucleus and cytoplasm were extracted by multivariate statistical methods and attributed to nucleic acids, lipids, and proteins. Finally, Raman spectral imaging was performed to show the distribution of these components within the cell.
Draux
Florence
F
Unité MéDIAN, Université de Reims Champagne-Ardenne, CNRS UMR 6237, UFR de Pharmacie, IFR53, 51 rue Cognacq-Jay, 51096 Reims Cedex, France.
Jeannesson
Pierre
P
Beljebbar
Abdelilah
A
Tfayli
Ali
A
Fourre
Nicolas
N
Manfait
Michel
M
Sulé-Suso
Josep
J
Sockalingum
Ganesh D
GD
D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D049109:Cell Proliferation; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008175:Lung Neoplasms / Q000473:pathology*; D013059:Spectrum Analysis, Raman / Q000379:methods; D014407:Tumor Cells, Cultured