Open AccessSelective imaging of saturated and unsaturated lipids by wide-field CARS-microscopy
Author(s) -
Christoph A. Heinrich,
Alexander Hofer,
Andreas Ritsch,
Christian Ciardi,
Stefan Bernet,
Monika RitschMarte
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.002699
Subject(s) - microscopy , raman scattering , raman spectroscopy , optics , materials science , excitation , signal (programming language) , analytical chemistry (journal) , chemistry , physics , chromatography , quantum mechanics , computer science , programming language
Wide-field Coherent Anti-Stokes Raman Scattering (CARS) microscopy is employed to identify saturated and unsaturated fatty acids in micro-emulsions and cells, using the ratio between the strong -C-H CARS signal at 2850 cm(-1) and the weak signal of the =C-H vibration around 3015 cm(-1) for distinction. Quantitative CARS imaging at the =C-H resonance is challenging, since it yields only a low CARS signal, and small differences on the order of 5% in the concentration of polyunsaturated fatty lipids have to be detected. For this purpose we draw advantage of the high signal-to-noise ratio of wide-field CARS microscopy that is achieved by an excitation geometry involving a "sheet-of-light"-type illumination.