Embryo Transfer Surgery.

Embryo transfer surgery is an essential step in the process of generating gene-modified mice, regardless of whether the embryos were modified by DNA, RNA CRISPR components, or embryonic stem cells, or whether they were microinjected or electroporated. Transfer is also a necessary step for assisted reproductive techniques such as rederivation and reanimation by in vitro fertilization. The manipulated embryos must be returned to the reproductive tract of a pseudopregnant recipient female mouse, wherein the transplanted embryos develop to term. Embryos may be transferred to either the oviduct or uterine horn, depending upon the developmental status of the embryos and the stage of the recipient. This chapter will describe the process of transferring embryos surgically to a recipient female.