Imaging of Histological Sections of the Human Intestine by Multimodal Cars Microscope

We demonstrate the capabilities of the coherent anti-Stokes Raman scattering (CARS) microscope and its multimodal operation to image a histological section of human intestinal tissue. The imaging of unstained and stained sections using various nonlinear optical contrasts was performed. The CARS configuration of our microscope allows probing which does not require a preliminary staining of tissue saving the treatment time and providing label-free investigation of original matter. Particular attention was paid to visualisation of unstained tissue. CARS images were recorded in the high wave number Raman spectroscopy region and the spectra of the most distinguished features of images are provided and discussed. Additionally, the two photon excitation fluorescence (TPEF) and second harmonic generation (SHG) contrast mechanisms were used for structural visualisation of both unstained and stained sections of human intestinal tissue. Visualisation of a histological section using all contrast mechanisms mentioned above is analysed and discussed. The research is aimed to draw attention to a potential of CARS/nonlinear microscopy in routine healthcare.