Imaging by Raman spectroscopy (RAMAN DXR2xi imager, ThermoFisher Scientific): each molecule has a unique spectral signature, determined by the Raman photons emitted after interaction with light. These photons are collected and analysed to provide information on the structure and chemical composition of the sample. We are mapping several thousand spectra on frozen tissue sections just a few microns thick.
Stimulated Raman imaging (SRS_microscope BondXplorer, Lightcore Technologies) complements spontaneous Raman spectroscopy. It can be used to target certain areas of interest in the spectrum in order to image chemical compounds. Acquisitions are therefore faster and can be carried out over larger fields of view.
Anti-Stokes Coherent Raman Scattering (CARS) microscopy provides high-resolution, high-speed, high-sensitivity, non-invasive imaging. It offers the possibility of visualising specific biomolecules without prior labelling.