Kallepitis, C. et al. Nat. Commun. 8, 14843 (2017).

Raman spectroscopy-based imaging is a label-free approach that provides rich chemical information on imaged samples. Recent innovations in this area have included 3D confocal Raman imaging, which has improved the volumetric imaging capabilities of this technique. However, identifying and quantifying biomolecules in these 3D images remains challenging. Kallepitis et al. addressed this challenge by developing quantitative volumetric Raman imaging (qVRI). qVRI is a computational framework that handles hyperspectral data sets from volumetric confocal Raman imaging, allows the relative abundances of different biomolecules to be determined within each voxel of an image and enables 3D visualization and quantification. The researchers used qVRI to study cells such as pluripotent stem cells, cardiomyocytes, monocytes and macrophages grown in 2D and 3D culture, giving views of these cells with impressive biomolecular specificity.