Improved in vitro development of the chick embryo using roller-tube culture

In vitro embryos culture has proved extremely useful in studying vertebrate development. To date, the most widely used method for culturing chick embryos from gastrula stages has been ring culture. Although such embryos can proceed normally to stage 12+ (17 somites) over an in vitro incubation time of some 30 h, the system requires considerable practice and is time consuming, limiting the number of cultures that can be set up. The vascular system and extra-embryonic blood supply, in particular, probably limit the extent of normal development in this system. A further, less widely used culture method allows very advanced development, but requires considerable skill and specialized apparatus. In addition, the thin egg albumin that has hitherto been the basis of successful media in both these culture systems precipitates phosphorothioate oligodeoxynucleotides that have been used in antisense experiments, thus interfering with gene expression in the whole embryo. We describe here a method for culturing chick embryos in albumin-free medium, using a roller system similar to that employed for rat and mouse embryos. The method is quick and simple, and gives improved development to stage 13 and beyond.