Cultured cells were fixed in 2.5% glutaraldehyde for a minimum of 1 hour. After transferring to Eppendorf tubes, they were washed in buffer and secondary fixed with OsO4 for 1 hour. The cells were then dehydrated in an alcohol series, resin infiltrated and the resin polymerised. The resulting blocks were sectioned with a Leica Ultracut E. The sections were then collected on 200 mesh thin bar copper grids, then stained with Uranyl acetate and Lead citrate. The sections were then examined in a JEOL JEM1400 TEM.