Scanning Electron Microscopy of the Extracellular Matrix of Amphibian Gastrulae by Freeze-drying

In order to demonstrate the extracellular matrix (ECM) which tends to be missing from specimens prepared by ordinary procedures, a freeze-drying method was applied to gastrulae of the newt ( Cynops pyrrhogaster ) without prefixation and the embryos were examined with a scanning electron microscope (SEM). It was revealed that a prominent amount of fibrillar ECM occupied the blastocoel and amorphous ECM covered the inner surface of the blastocoelic wall (BW) as well as the surface of migrating cells. These results were compared with those obtained from observations of specimens fixed chemically.