Em 301 electron microscope

Term placentas from 96 Bolivian individuals were collected from La Paz, Bolivia (high-altitude; 3,600 m n = 48) and Santa Cruz, Bolivia (low-altitude; 400 m n = 48). Of our 96 individuals 48 were of European ancestry and 48 were of Andean ancestry. The placentas were from healthy, term (≥ 37 weeks gestation), singleton pregnancies in individuals without pregnancy complications delivered via elective caesarian section. All women gave written informed consent to protocols approved by the Bolivian National Bioethics Committee, the Universidad Mayor de San Andrés, Instituto Boliviano de Biología de Altura Consejo Tecnico, and the United States Institutional IRB from the University of Medicine and Dentistry, New Jersey Medical School in Newark, NJ (now Rutgers). Tissue for transmission electron microscopy was rinsed three times over a 24-h period in 0.1 M sodium cacodylate, pH 7.4, and then post-fixed in 1% osmium tetroxide in cacodylate buffer at 4°C for 1 h. After a brief rinse in buffer the tissue was dehydrated in ascending concentrations of alcohol, embedded in Taab resin, and polymerized at 60°C for 36–48 h. Ultrathin sections were cut on an LKB ultramicrotome, and grids were stained with uranyl acetate and Reynold’s lead citrate prior to examination in a Phillips EM 301 electron microscope (Figure 1).

Eyes from adult (less than 6 months old) opticin null mice and wild type C57BL/6 mice were fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.4, at room temperature. The eyes were then dehydrated in an ascending ethanol series then incubated in propylene oxide prior to embedding in Taab resin (Taab Laboratories Equipment, Aldermaston, UK). Ultrathin sections were cut and stained with 2% uranyl acetate and Reynolds lead citrate. Electron micrographs were taken at 60 kV with a Philips EM 301 electron microscope.