A NEW TECHNIQUE FOR CULTURING RAT EMBRYOS BETWEEN GESTATION DAY-14 AND DAY-15

A method for culturing rat embryos between days 14 and 15 has been dev eloped. On gestation day 14 (morning of sperm and plug = day 0), lapar otomies were performed on time-mated rats that had been anaesthetized with halothane. The embryos, with open attached yolk sacs and placenta s, were cultured in 650-ml plastic flasks with 120ml medium (0.7% bovi ne serum albumin in Earle's balanced salt solution with antibiotics, p rewarmed to 37 degrees C and continuously flushed with water-saturated 95% O(2)5% CO2, pH 7.4) in a Dubnoff metabolic shaker with gentle agi tation. Viability and morphology were assessed after 26 hr in culture. On day 15, embryonic growth and development were similar to that in i n vivo controls, and viability was high (55%).