Applications of Two-Photon Fluorescence Microscopy in Deep Tissue Imaging

Based on non-linear excitation of fluorescence molecules, two-photon fluorescence microscopy has become a significant new too for biological imaging. The point-like excitation characteristic of this technique enhances image quality by the virtual elimination of off-focal fluorescence. Furthermore, sample photodamage is greatly reduced because fluorescence excitation is limited to the focal region. For deep tissue imaging, two-photon microscopy has the additional benefit in the greatly improved imaging depth penetration. Since the near-infrared laser sources used in two-photon microscopy scatter less than their UVglue-green counterparts, in-depth imaging of highly scattering specimen can be greatly improved. In this work, we will present data characterizing both the imaging characteristics point-spread- functions and tissue samples skin images using this novel technology. In particular, we will demonstrate how blind deconvolution can be used further improve two-photon image quality and how this technique can be used to study mechanisms of chemically-enhanced, transdermal drug delivery.