The Raman Map of the Human Cell

Cell activity is governed by its subcellular compartments, each playing a specialized role essential to the overall function. Among various methods used for cell analysis, Raman microscopy is unique, enabling the study of single living cells at a submicron resolution. It is used for phenotyping of cells, monitoring the mechanisms of various stimuli or drugs, or tracking cell metabolism in real time. However, localizing specific organelles and identifying their components remain a challenge. Therefore, the "Raman Map of the Cell" aims to provide a reliable method for subcellular analysis and cataloging the Raman spectra of prominent cell organelles. In this study, we focused on endothelial cells due to their prevalence and widespread application in biomedical research. Using Raman imaging and advanced chemometric techniques, we mapped the subcellular landscape of a single endothelial cell. Individual organelles, including the nucleus, nucleoli, perinuclear area, mitochondria, lipid droplets, and cytoplasm, were localized, and their spectra were compared with those of reference compounds. As a result, we have established a comprehensive library of Raman profiles for cellular organelles, highlighting their marker bands for precise identification. The "Raman Map of the Cell" is discussed alongside relevant data from our previously published reviews on important molecules that occur naturally in biological systems, including proteins, lipids, and carbohydrates.