Combined AFM/Raman microspectroscopy for characterization of living cells in near physiological conditions

Raman microspectrosopy (RM) is a noninvasive, label-free, molecular spectroscopy method used to record the vibrational spectroscopic fingerprints based on molecular bonds and has been recently applied to characterize living cells. Atomic force microscopy (AFM) is a high-resolution form of scanning probe microscopy that can provide information including surface topography, cell adhesion, and cellular elasticity of single cell. By exploiting the advantages of these two microscopies, we have applied a combined AFM/RM technique to investigate both biomechanical and biochemical properties of living cells in near physiological conditions. The model cells involved were bacterial cells (e.g. Pseudomonas putida) and mammaliam cells (e.g. human lung cancer cells and breast cancer cells) in physiological conditions. The overall objective of this chapter is to provide new insightful information on molecular structural, cell cytoarchitectural, and biomechanical properties from bacterial cells to human cancer cells at the single cell level, and to discuss applications of conbined AFM/RM in single cell studies.