Abstract: Objective To explore some methods of obtaining fetuses of 30 days by surgical operation and the ways of the fetal fibroblasts culture. Methods Identified the estrus of female Beagles for timed mating, then observed development of the fetues to determine the time of pregnancy by B-ultrasonic examination. When the female beagle was 30 days pregnant, removed the fetuses from its one side of the uterus by surgical operation, and then separated fetal fibroblasts with trypsin digestion after removing its head, limbs and internal organs. The cells were cultured and passaged in vitro. Meanwhile, the remaining fetuses of the other side of the uterus were retained, and the female Beagle was nursed carefully to insure development of the fetuses. Results Successfully isolated and cultured the canine fetal fibroblasts, and kept the remaining fetuses developing to full term and survived. Conclusion This experiment reserved the female dog which can be used as receptor for embryo transfer; the remaining pups can be used as the control group of the full-sib relationship for cloning Beagles in the future.

Key words: In vivo, Beagles, Fetal fibroblast