1,2-Dioleoyl-rac-glycerol-13C3 is intended for use as an internal standard for the quantification of 1,2-dioleoyl-rac-glycerol by GC- or LC-MS. 1,2-dioleoyl-rac-glycerol is a diacylglycerol that contains oleic acid at the sn-1 and sn-2 positions. It effectively binds the C1 domain to activate conventional protein kinase C forms and serves as a substrate for diacylglycerol kinases and multisubstrate lipid kinase.1,2,3