A. Oocytes for pronuclear injection are collected from females that have been hormonally stimulated to cause superovulation. The eggs are flushed from the oviducts following euthanasia of the donor. After pronuclear injection of the DNA, the embryos are surgically injected into the oviducts of recipient females.
B. Transgenic mice will be screened by removal of approximately 1 cm of the tail tip from which DNA is then extracted. This procedure inflicts minimal discomfort, and therefore, requires no anesthetic. Usually bleeding is not a problem, however, the vessels can be electrically cauterized if needed.