In vivo nonlinear spectral imaging in mouse skin.

We report on two-photon autofluorescence and second harmonic spectral imaging of live mouse tissues. The use of a high sensitivity detector and ultraviolet optics allowed us to record razor-sharp deep-tissue spectral images of weak autofluorescence and short-wavelength second harmonic generation by mouse skin. Real-color image representation combined with depth-resolved spectral analysis enabled us to identify tissue structures. The results show that linking nonlinear deep-tissue imaging microscopy with autofluorescence spectroscopy has the potential to provide important information for the diagnosis of skin tissues.