Deuterium Raman imaging for lipid analysis.

Raman microscopy has been used to deduce information about the distributions of endogenous biomolecules without exogenous labeling. Several functional groups, such as alkynes (CC), nitriles (CN), and carbon-deuterium (C-D) bonds, have been employed in recent years as Raman tags to detect target molecules in cells. In this article, we review some recent advances in applications using deuterated fatty acids for lipid analysis, such as investigation of tumor-selective cytotoxicity of γ-linolenic acid (GLA), simultaneous two-color imaging of stearate and oleate using deuterated and protonated alkynes, Raman hyperspectral imaging, and analyses of the physical properties of lipids through spectral unmixing of the C-D vibrational frequencies. In addition, we review some advanced methods for observing intracellular metabolic activities, such as de novo lipogenesis from deuterium-labeled precursors.