Abstract
Rat ova in the early stage after fertilization were subjected to the double fixation with glutaraldehyde and osmium combined with critical point drying. Then they were observed by the scanning electron microscope. After that, they were soaked in QY-1 and embedded in epon. Ultrathin sections were prepared for them by means of MT-1 and observed by transmission electron microscopy.
These sections were potentially available for scanning and transmission electron microscopy to observe peripheral changes and inner development of the ovum with the lapse of time in the early stage after fertilization.