The human egg in the pronuclear stage



A human egg in the pronuclear stage was recovered by flushing the excised oviduct that had been removed along with the uterus. The hysterectomy and right salpingectomy were performed on day 16 of the patient's menstrual cycle. The egg was examined first in the fresh state and revealed two pronuclei, a granular zona pellucida, and corona cell processes traversing the zona pellucida. The egg was subsequently fixed and stained revealing further details of the pronuclei, and the tail of the fertilizing spermatozoon lying over one of the pronuclei.

The age of the egg was estimated as being 3 to 50 hours post ovulation time.