Ultrathin sections (70∼80 nm) were obtained using a Reichert Jung Ultracut S microtome (Leica, Vienna, Austria), mounted on grids, stained with uranyl acetate and lead citrate, and analyzed under a Zeiss EM 902 A electron microscope (Leo, Oberkohen, Germany).
For EDX microanalysis, sections 200 nm thick were also stained with uranyl acetate and mounted on carbon-coated titanium grids.
The biopsies collected were snap-frozen in liquid nitrogen after mounting them on acetate paper.
This comprised a shell manufactured from ~3.2-mm-thick cellulous acetate butyrate (CAB) mounted on a polycarbonate end plate, a transparent plastic selected because of its low water absorption and its strength.
Serial ultrathin sections from each of the species were cut with a diamond knife, mounted on Cu grids, stained in uranyl acetate and lead citrate, and then observed under a Philips CM 10 (FEI, Eindhoven, The Netherlands) transmission electron microscope (TEM) operating at 80 kV.
Ultrathin sections (80 90 nm) were then cut with an ultramicrotome (Ultracut E; Riechert-Jung, Leica, Vienna, Austria), mounted on copper grids, counterstained with uranyl acetate and lead citrate, and evaluated in the electron microscope (CM120 Biotwin; FEI Company, Electron Optics, Eindhoven, The Netherlands).
Ultra-thin sections (70 nm) were mounted on grids, contrast enhanced with uranyl acetate and lead citrate and examined with a Philips EM 400 T electron microscope (Philips GmbH, Germany) as previously described.
Thin sections (60 80 nm) were cut with an ultramicrotome Ultracut S (LEICA Microsystems), mounted on copper grids, stained with uranyl acetate and lead citrate, and examined at 80 kV in a JEM-1210 electron microscope (JEOL; Tokyo, Japan).
Thin sections (silver in interface) from the resin blocks were mounted on copper grids, stained with uranyl acetate and lead citrate and examined using JEOL or Hitachi electron microscopes.
Ultrathin sections were prepared with a Reichert Jung ultracut microtome, mounted on nickel grids, contrasted with uranyl acetate and lead citrate, and examined in a Libra 120 electron microscope at 80 kV.
