Palmitoyl Thio-PC is a thioester analogs of glycerophospholipids, in combination with Ellman’s reagent, are convenient colorimetric substrates for the measurement of phospholipase (PL) activity. Palmitoyl thio-PC is a chromogenic PLA2 substrate that contains a palmitoyl thioester at the sn-2 position of the glycerol backbone. Hydrolysis of the thioester by PLA2 yields a free thiol that reacts readily with DTNB (Ellman’s reagent) giving a bright yellow product with an absorbance maximum at 412 nm. Palmitoyl thio-PC has been used to measure bee venom sPLA2 activity in a phospholipid:Triton X-100 mixed micelle system.