820 scanning electron microscope

EMPA of mineral compositions were determined using a Cameca SX-100 electron microprobe, using energy-dispersive spectrometry at the University of Cambridge (15 kV, 10 nA; beam diameter 5 μm) with fayalite, rutile, corundum, periclase and pure Co, Ni, Mn, Cr, Zn and Cu standards (Supplementary Table 4). Spectra were collected with a PGT prism 2,000 ED detector and the data reduced with the PGT excalibur software. Back-scatter electron and secondary electron images were obtained using the JEOL 820 scanning electron microscope in the Department of Earth Sciences, University of Cambridge, with an accelerating voltage of 20 kV and 1 nA beam current.

To examine the presence of pinopodes in luminal epithelium, one part of the specimens was fixed in 0.1 M PBS (pH 7.4) containing 2.5% glutaraldehyde overnight, The samples were washed twice in buffer containing sodium cacodylate and calcium chloride (pH 7.4) and once in distilled water. Thereafter, they were dehydrated, first in increasing concentrations of ethanol (70, 95, and 99.5%), and then in acetone, and dried in a critical point drier with carbon dioxide. The specimens were mounted on a specimen holder, coated with platinum, and examined using a JEOL 820 scanning electron microscope (JEOL, Tokyo, Japan). Scanning electron micrographs of pinopodes were obtained from 10 randomly selected areas of each tissue specimen and were graded semiquantitatively. Based on the literature, pinopode coverage of the uterine endometrium can be scored as follows: 0 (absence of pinopodes), 1 (covering < 25% of the surface epithelium, few), 2 (covering 25–50% of the surface epithelium, moderate), or 3 (covering > 50% of the surface epithelium, abundant) [14 (link)]. A single score was assigned to the most representative photomicrograph of the 10 images obtained for each tissue specimen.