Probing oxidative stress in single erythrocytes with Raman Tweezers

Raman Tweezers have been successfully applied to characterize chemically-induced oxidative stress on optically-trapped live, single erythrocytes. There is significant enhancement in Raman peak intensities corresponding to S. S and C-S stretching modes that are induced by oxidative stress. This is consistent with the formation of mixed disulphides between protein SH groups and low-molecular-mass thiols such as glutathione during oxidative damage to cells. Enhancement in glutathione level as a protective response against oxidative stress has been observed. Principal component analysis of the data yields good discrimination between spectra of normal and stress-induced red blood cells.