Formvar supporting membranes

After 3 rinses in 0.15-M sodium phosphate buffer (pH 7.2), the tissue samples were postfixed in 1% OsO₄ in 0.15-M sodium phosphate buffer (pH 7.2) for 2 h. Following dehydration in a graded series of ethanol, the specimens were transferred to propylene oxide and embedded in Epon (TAAB Laboratories Equipment Ltd., Aldermaston, UK). Ultrathin sections were cut with a Reichert-Jung Ultracut E microtome (Leica Microsystems), collected on 1-hole copper grids with formvar supporting membranes (Merck, Darmstadt, Germany) and stained with uranyl acetate and lead citrate. A Philips CM 100 transmission electron microscope (Philips, Amsterdam, the Netherlands) was used to view the sections, and digital images were obtained with an Olympus Soft Imaging Solutions (OSIS) Veleta side-mounted CCD camera (Olympus, Tokyo, Japan).

Following 3 rinses in 0.15 M sodium phosphate buffer (pH 7.2), the specimens were postfixed in 1% OsO₄ in 0.15 M sodium phosphate buffer (pH 7.2) for 2 h. After dehydration in a graded series of ethanol, the samples were transferred to propylene oxide and embedded in Epon (TAAB Laboratories Equipment Ltd., Aldermaston, UK). Ultrathin sections were cut with a Reichert-Jung Ultracut E microtome (Leica Microsystems), collected on 1-hole copper grids with formvar supporting membranes (Merck, Darmstadt, Germany) and stained with uranyl acetate and lead citrate. A Philips CM 100 transmission electron microscope (Philips, Amsterdam, The Netherlands) was used to view the sections, and digital images were obtained with an Olympus Soft Imaging Solutions (OSIS) Veleta side-mounted CCD camera (Olympus, Tokyo, Japan).