Label-free Molecular Imaging of Living Cells

Abstract

Raman scattering, coherent anti-Stokes Raman scattering (CARS), harmonic generation can be used to image biological molecules in living cells without labeling. Raman scattering and CARS detect frequencies of molecular vibrations and use them to obtain the molecular distributions in samples. Second-harmonic generation is generated in array structures of noncentrosymmetric molecules and can be used to detect proteins, such as, collagen, myosin and tubulin. Since labeling techniques using chemical and biological reactions may cause a undesirable change in the sample, label-free molecular imaging techniques are significant for observation of living samples.