H 700 electron microscope

DT40 cells (2–3 × 10⁶) were collected by scraping at the indicated time points after vvIBDV infection and centrifuged at 1,000 × g for 10 min at 4 °C. The pellets were washed in PBS and fixed in 2.5% glutaraldehyde. The cells were then post-fixed in 1% OsO₄ and embedded in EPON-812. Ultrathin sections were cut and examined under a Hitachi H-700 electron microscope.

For light microscope histology, paraffin-embedded 5-μm-thick sections were stained with haematoxylin and eosin and with PAS. The von Kossa staining method 10 was used to reveal calcium concretions, and scanning electron microscopy (SEM) was used to analyse their composition.
For SEM, ultra-thin sections were cut from Epon-embedded tissue blocks, counterstained with uranyl acetate followed by lead citrate, and examined with a Hitachi H-700 electron microscope. (Hitachi, Chiyoda, TKY)

Muscle biopsy was performed in four patients. Biopsy specimens were either frozen in liquid nitrogen-cooled isopentane for histochemistry or fixed with glutaraldehyde for electron microscopy. Transverse serial frozen sections of 10-μm thickness were stained with hematoxylin and eosin, modified Gomori trichrome, and a battery of histochemical methods. For electron microscopy, biopsy specimens were fixed in buffered 2% isotonic glutaraldehyde at pH 7.4, post-fixed in osmium tetroxide, and embedded in epoxide resin. Ultrathin sections were stained with uranyl acetate and lead nitrate and examined with an H-700 electron microscope (Hitachi, Tokyo, Japan).