Application of corrosion cast method for scanning electron microscopic observation of mouse embryo vasculature.

We described a method for making vascular corrosion casts of mouse embryos and applied it to study the vasculature of the whole body mouse embryo at 13.5 days (body length 9-11 mm) to 18.5 days (body length 18-23 mm), as well as that of its respective organs. The Mercox resin was perfused via the umbilical vessels using a special needle made by pulling the hematocrit tube (caliber 100-200 microns). The specimens were treated with 10% NaOH, rinsed, dried, coated with gold and observed under a scanning electron microscope. Visceral organs of a 13.5 day embryo were rather immature, but the liver vasculature was relatively well developed. In a 15.5 day embryo, the whole body vasculature was relatively well developed and the features of respective organs could be identified. In a 18.5 day embryo, almost all organs and extremities were well developed, but sensory organs in some parts showed immature development.