Diheptanoyl Thio-PC is a substrate for all PLA2s with the exception of cPLA2 and PAF-AH.{5681} Interaction of this compound with a PLA2 results in cleavage of the sn-2 fatty acid generating a free thiol on the lysophospholipid. This free thiol can be detected using chromogenic substrates such as DTNB (Ellman's reagent) and DTP.{1358,1359}