Extending the limits of avian embryo culture with the modified Cornish pasty and whole-embryo transplantation methods.

The New and Early Chick (EC) methods, two commonly used techniques for ex ovo culture of early-stage avian embryos, are limited by poor survivability after initiation of circulation. This limitation is circumvented with two recent technical advancements: the modified Cornish pasty culture and whole-embryo transplantation. The former supports optimal ex ovo growth till stage HH18, and the latter allows ex-ovo-manipulated embryos to have long-term in ovo-survivability. Here we provide step-by-step instructions for both methods. These two new techniques can also be combined to achieve targeted labeling, imaging and electroporation in early-stage embryos ex ovo, and phenotypic and functional analyses at more advanced developmental stages in ovo.