Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence

Multiphoton microscopy relies on nonlinear light-matter interactions to provide contrast and optical sectioning capability for high-resolution imaging. Most multiphoton microscopy studies in biological systems have relied on two-photon excited fluorescence (TPEF) to produce images. With increasing applications of multiphoton microscopy to thick-tissue "intravital" imaging, second-harmonic generation (SHG) from structural proteins has emerged as a potentially important new contrast mechanism. However, SHG is typically detected in transmission mode, thus limiting TPEF/SHG coregistration and its practical utility for in vivo thick-tissue applications. In this study, we use a broad range of excitation wavelengths…

• UD
  U.S. Department of Energy
• NI
  National Institutes of Health