10 mls of wash buffer followed by scraping the cells approximately 1 u00d7 10 7 were placed in a conical tube and centrifuged one ml of wash buffer plus 1 mm phenylmethane sulfonyl fluoride 100 um leupeptin and 100 um pepstatin a was added to the pellet and the cells were lysed using a probe sonicator model w 385 heat systems ultrasonics with a stepped microtip at an output setting of 1 sonication was repeated six times for 15 seconds at 45 second intervals the transfected 293 lysates were then assayed for cpla 2 activity according to example 1 the results from one such lysate are shown in fig5 where cpla 2 activity is plotted against the protein content of the lysate untransfected cells otherwise handled in an identical manner were used as the negative control the graph clearly shows that the transfected cells had higher cpla 2 activity than did the negative control the increased enzymatic activity demonstrates that plasmid phdcpfs was able to successfully express cpla 2 stable expression of cpla 2 was achieved in the human embryohal kidney cell line 293 and in the av12 hamster cell line the av12 cell line is a permanent part of the atcc and is available under accession number crl9595 and the 293 cell line is a permanent part of the atcc and is available under accession number crl1573 plasmids containing the cpla 2 encoding gene were prepared according to example 3 a both mammalian cell lines were transfected with phdcpfs according to example 3b except that the plasmid dna was first linearized by digestion with restriction enzyme fsp i and precipitated with ethanol after transfection both cell lines were individually seeded into culture plates and grown for three days in dmem after.