A technique of cell culture on collagen substrate is proposed for cytogenetic studies on domestic animal embryos. The embryonic cells sampled by biopsy or micromanipulation grow on collagen coated cover slips in Leighton tubes with Ham's F12 medium, supplemented with 20 percent fetal calf serum. This method may be used to study the embryonic karyotype induced by a structural abnormality, as well as the karyotype of domestic animal embryos before transfer.