Avanti’s phospholipids are prepared using a precursor (GPC) derived from soybean lecithin, therefore the stereochemistry of the chiral carbon is dictated by the biological system from which it was derived. Since biological systems only manufacture the L-isomer, Avanti’s phospholipids are 100% L-isomer form. We have confirmed this by optical rotation and enzymatic digestion using phospholipase A2 (PLA2). PLA2 cleaves the sn-2 ester bond generating LPC and free fatty acid. The enzyme is specific for the L-isomer form, in fact the D-isomer acts as a competitive inhibitor. Treatment of Avanti’s synthetic PC’s results in complete digestion of the diacyl compound indicating absolute stereochemical purity. Spiking Avanti’s PC with 1% D-isomer PC as a control produces incomplete digestion (>1% residual diacyl PC remaining).