In this report, the ultrastructure of eM was studied by cryo-scanning electron microscopy (cryo-scan), which enabled us to observe the sample while it still contained water. … It was then placed in a specially made chamber which was part of the cryo-scanning electron microscope model JSM-50A (JEOL, Tokyo). The eM was examined after etching and coating with gold. A human cervical mucus specimen as observed by cryo-scan. The 3-dimensional netlike structure was characteristic (original magnification x 10,000).