Chemical imaging of tissue in vivo with video-rate coherent anti-Stokes Raman scattering microscopy.
Imaging living organisms with molecular selectivity typically requires the introduction of specific labels. Many applications in biology and medicine, however, would significantly benefit from a noninvasive imaging technique that circumvents such exogenous probes. In vivo microscopy based on vibrational spectroscopic contrast offers a unique approach for visualizing tissue architecture with molecular specificity. We have developed a sensitive technique for vibrational imaging of tissues by combining coherent anti-Stokes Raman scattering (CARS) with video-rate microscopy. Backscattering of the intense forward-propagating CARS radiation in tissue gives rise to a strong epi-CARS signal that makes in vivo imaging possible. This substantially large signal allows for real-time monitoring of dynamic processes, such as the diffusion of chemical compounds, in tissues. By tuning into the CH(2) stretching vibrational band, we demonstrate CARS imaging and spectroscopy of lipid-rich tissue structures in the skin of a live mouse, including sebaceous glands, corneocytes, and adipocytes, with unprecedented contrast at subcellular resolution.
Evans
Conor L
CL
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
Potma
Eric O
EO
Puoris'haag
Mehron
M
Côté
Daniel
D
Lin
Charles P
CP
Xie
X Sunney
XS
D000818:Animals; D004058:Diffusion; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D008807:Mice, Inbred BALB C; D008853:Microscopy / Q000379:methods*; D008899:Mineral Oil / Q000378:metabolism; D012542:Scattering, Radiation; D012867:Skin / Q000378:metabolism; D013059:Spectrum Analysis, Raman / Q000379:methods*
D008899:Mineral Oil