After washing in buffer, cells were dehydrated in an ascending series of aqueous ethanol and transferred via a mixture of ethanol and Epon to pure Epon 812 as embedding medium.
After 3 rinses in cacodylate buffer, cells were dehydrated in a gradient series of ethanols from 30 50%, en bloc stained with saturated uranyl acetate in 50% ethanol for 1 hour, carried through to 100% ethanol, then infiltrated in 1 part 100% ethanol: 1 part Spurr's Low Viscosity Resin overnight at room temperature.
After washes with PB buffer, cells were dehydrated in 70, 80, 95 and 100% ethanol (10 min for each procedure), and then the cells were further dehydrated in 100% acetone two times for 10 min each at RT.
After additional washes in buffer, the cells were dehydrated and embedded with Epon 812 (Shell Chemical, UK), followed by polymerization.
After washing with the phosphate buffer, the cells were dehydrated in a series of ethanol solutions of 30%, 50 %, 70 %, 95 and 100% for 50 min, and then embedded with Epon 8100%Shell Chemical, London, UK) for polymerization.
After extensive rinsing with buffer A, cells were dehydrated through increasing concentrations of ethanol (50, 70, 90 and 100%).
After washed twice in phosphate buffer, the cells were dehydrated through serial graded concentrations of ethanol (35, 70, 95 and 100%, respectively) for 15 min, then infiltrated and embedded in Spurr's resin.
After rinsing 3 times in DIW to remove any buffer salts, cells were dehydrated by multiple exchanges in progressively higher ethanol concentrations up to 100%, followed by two exchanges in dry 100% acetonitrile.
After being washed for 15 min in 0.075 mol/L phosphate buffer and 0.19 mol/L sucrose buffer at 4°C, the cells were dehydrated with a graded series of ethanol and gradually infiltrated with epoxy resin.
After postfixation with 1% OsO4 in 0.2 M cacodylate buffer (pH 7.3) at room temperature for 30 min, cells were dehydrated with ascending concentrations of ethanol, and embedded in epoxy resin (TAAB Laboratories Equipment Limited, Aldermarton, UK).
After two more washes with cacodylate buffer, samples were pelleted in 2% agarose (ultra-low gelling temperature, Sigma-Aldrich) and cells were dehydrated by incubation in an ascending series of aqueous ethanol for 15 min per incubation step.
