Growth of Explanted Eight Day Hamster Embryos in Circulating Medium

Abstract

THE conditions for culture of Syrian hamsters (Cricetus auratus) in a circulating medium¹ have been investigated as a means of facilitating the direct teratological effects of chemical carcinogens. Female virgin (80–120 g) hamsters determined, by inspection, to be in oestrus between 2200 h and 2400 h, were placed in the male's breeding cage. The hamsters were separated the next morning, the first day of pregnancy. Pregnant hamsters were killed by an overdose of ether on day 7, 8 or 9. The uterus was removed aseptically and placed in a Petri dish of sterile Dulbecco's phosphate buffered saline (PBS). The uterus was opened under a stereoscopic microscope, and the embryo with decidua was removed and placed in a second Petri dish containing PBS. The decidua was removed and Reichert's membrane torn with watchmaker's forceps and microdissecting scissors. The isolated embryos with intact foetal membranes were kept in PBS until they were placed in culture vessels. The time from the removal of the uterus to the embryos being placed in culture vessels varied from 45 to 90 min.