Collection of fertilized one-cell mouse eggs for microinjection.

Following superovulation and mating, the immature F1 females are killed, and the fertilized F2 eggs are dissected out from the upper part of the oviduct or ampulla. The procedure for egg collection is described in the present chapter. Eggs may be recovered several hours before they are due to be injected. A suitable time for collection would be 11 AM to 12 noon for animals maintained on a light-dark cycle with the mid-dark-phase time at 12 midnight. The procedure is straight-forward, and once the use of the mouth-operated pipet holder is mastered, the vast majority of eggs from 10 mice can be obtained in <1 h.