1-Thioglycerol is a reagent used in fluorescence, spectroscopy, and microbiology techniques. Varying the concentration of 1-thioglycerol in the preparation of CdSe/CdS core-shell ultrasmall quantum dots (CS-USQDs) allows a precise way to control the size of the shell, with shell size increasing with increased concentration. It is used as a capping agent in the synthesis of nanocrystals analyzed via Raman and UV/Vis spectroscopy. Biologically, 1-thioglycerol stimulates porphyrin synthesis and increases glutamyl-tRNA reductase activity in E. coli grown in an aerobic environment. It was previously a component in hair permanents used to produce waves or curls.