The specimens prepared for SEM were fixed in 3% glutaraldehyde in 0.1M phosphate buffer, pH 7.2 for 2 hours. Cell suspensions were then adhered to coverslips coated with 0.1% poly-L-Lysine for further processing. Each coverslip was placed in individually labelled porous pots to facilitate handling during processing. The porous pot containing cells were washed in 0.1M Phosphate buffer (2 x 10minutes) and post fixed in 1% osmium tetroxide in deionised water for 1 hour. The specimens were then washed as before in phosphate buffer and gradually dehydrated through increasing concentrations of ethanol for 10 minutes each ( 50%, 75%, 95%, 100%, 100%, 100% ). The specimens were dried in a Denton critical point drier and mounted on SEM stubs with carbon tape. The specimens were then coated with gold palladium in a Microvac sputter coater and examined at 20kV in a Jeol JSM T-300 SEM.

Cell Suspension Preparation for TEM

The cell suspensions were fixed in 3% glutaraldehyde in 0.1M phosphate buffer, pH 7.2 for 2 hours. Cell pellets were made by centrifuging cells for 10minutes at 2000rpm. The pellet was suspended in warm agar and centrifuged again to form a agar cell pellet which was diced into 1mm cubes. The cells were then washed in 0.1M Phosphate buffer (2 x 10minutes) and post fixed in 1% osmium tetroxide in 0.1M Phosphate buffer. The cells were then washed in 0.1M Maleate buffer prior to enbloc staining with 2% Uranyl Acetate in 0.1M Maleate buffer. The cells were then dehydrated in an increasing series of Acetone solutions ( 50, 75,95,100,100,100%) and infiltrated and embedded in Spurrs Epoxy Resin. Ultrathin sections were made using a Leica Ultracut R and post stained with Reynold's Lead Citrate. The sections were examined in an Hitachi H600 TEM operating at 100kV.