Prolonged and simplified in vitro culture of explanted chick embryos

The method described in this paper allows explanted chick embryos to develop normally in vitro from the 2nd to the 5th day of incubation. The embryos are explanted with the aid of a ring of filter-paper and are fixed between two steel-rings dorsal side up for cultivation. The lower ring contains a mixture of yolk and albumen as culture medium. 40% of the explanted embryos reach the 5th day of development (stage 25, Hamburger and Hamilton). The maximum time of culture is 70 h after explantation.