Abstract
Purpose:
Raman scatting, which is the inelastic scatting of a photon, has molecular-specific wavelength distribution. The analysis using coherent Raman scatting can visualize molecular structural information in vivo without pretreatments, tissue preparations and staining.<br /> In this study, we developed a new coherent Raman microscope using white-light laser source and try to observe various molecular localization of rat cornea ex vivo.
Methods:
The cw Q-switched microchip Nd : YAG laser is used as the light source.<br /> The output beam ( 1064 nm ) is divided into two. The one is used directly as the pump radiation, and the other is used as seed laser pulses which are introduced into a photonic crystal laser ( PCF ) to generate supercontinuum ( SC : white-light laser ) for Stokes radiation. We irradiate these two kinds of laser light to rat cornea, soaked normal saline, and analyzed the transmitted coherent anti-Stokes Raman scatting ( CARS ), signals by mycrospectroscopy.
Results:
Analyzing CARS spectrum, we obtained stereoscopic information about molecular localization of purine ring, phenylalanine moiety, CH2 stretch. It means that we can get 3D image about localization of nucleic acid, protein, and lipid in cornea.
Conclusions:
We succeeded in development the multimodal nonlinear spectral imaging microscope which can visualize localization of nucleic acid, protein, and lipid in cornea. Using this technology, detailed molecular structural information will be observed with slit-lamp microscope near future.