Samples of microspore-derived
embryo-like globular structures as well as callus-like
structures were fixed in Karnovsky fixative solution
(4 % formaldehyde ? 5 % glutaraldehyde in 0.025 M
cacodylate buffer, pH 7), dehydrated in ethanol series,
embedded and polymerized in EM-bed 812 resin
(Electron Microcopy Sciences).