10 fetal bovine serum and antibiotic and antimycotic solutions cells were then grown to confluence for 2 days at confluence the medium was removed and cells were washed with serum free dmem and each well dosed with 200 u03bcl of a solution of gum mastic in serum free dmem each dosing was replicated in the total of six wells gum mastic was used at concentrations indicated in table 1 below control did not contain gum mastic after 24 hours the gum mastic control solution was removed and cells were redosed with 100 u03bcl of a solution of gum mastic in serum free dmem after 24 hours the gum mastic control solution was again removed and stored over the weekend at 4 u00b0 c with protease inhibitor aprotinin from sigma in a ratio of aprotinin to water of 1 200 the gum mastic was then diluted in dmem approximately 20 u03bcl sample in 200 u03bcl dmem nitrocellulose membrane and 3 sheets of filter paper were soaked in tris buffered saline tbs ph 7 3 biorad slot blot apparatus biorad labs ca was set up with filter paper on bottom membrane on top and tightened 100 ml tbs was added per well vacuum.