Analytical Techniques for Single-Cell Biochemical Assays of Lipids

Abstract

Lipids are essential cellular components forming membranes, serving as energy reserves, and acting as chemical messengers. Dysfunction in lipid metabolism and signaling is associated with a wide range of diseases including cancer and autoimmunity. Heterogeneity in cell behavior including lipid signaling is increasingly recognized as a driver of disease and drug resistance. This diversity in cellular responses as well as the roles of lipids in health and disease drive the need to quantify lipids within single cells. Single-cell lipid assays are challenging due to the small size of cells (∼1 pL) and the large numbers of lipid species present at concentrations spanning orders of magnitude. A growing number of methodologies enable assay of large numbers of lipid analytes, perform high-resolution spatial measurements, or permit highly sensitive lipid assays in single cells. Covered in this review are mass spectrometry, Raman imaging, and fluorescence-based assays including microscopy and microseparations. Expected final online publication date for the Annual Review of Biomedical Engineering, Volume 25 is June 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Lipid metabolism analysis in esophageal cancer and associated drug discovery

“…When combined with microscopy, Raman-based technologies allow for the non-destructive identification and imaging of specific lipid molecules present in the sample by analyzing the Raman scattering patterns [ 83 , 84 ]. However, Raman-based imaging techniques face challenges in identifying molecules with similar vibrational modes and detecting low concentrations of lipids [ 85 ]. Compared to Raman-based techniques, fluorescence microscopy offers higher sensitivity for measuring extremely low concentrations of cellular lipids, although it does not possess the same level of specificity as MS [ 85 ].…”

“…However, Raman-based imaging techniques face challenges in identifying molecules with similar vibrational modes and detecting low concentrations of lipids [ 85 ]. Compared to Raman-based techniques, fluorescence microscopy offers higher sensitivity for measuring extremely low concentrations of cellular lipids, although it does not possess the same level of specificity as MS [ 85 ]. Using fluorescent probes, fluorescence microscopy is primarily employed for imaging plasma membranes, organelle membranes, and lipid droplets [ 86 ].…”