Chicken blastodermal cell (CBC) culture is a useful tool for the production of germline and somatic chimeras. The long-term culture of CBCs may be used for studying the in vitro effects of various cytokines and growth factors at different stages of embryonic development (1 ). In addition, cell culture may prove to be a useful tool for the introduction of a genetic modification into the genome through transfection (2 ) and the selection of the cells carrying the modified gene conferring antibiotic resistance and/or the ability to grow in selective media before the cells are introduced into a recipient embryo in which they would colonize the germ line (3 ).