The purpose of this project was to observe the ex ovo early development of chick embryos. Our goals were to be able to routinely maintain normal development up to embryonic day 10, and to be able to analyze the normality of development by using a skeletal staining technique to observe both cartilage and bone formation. In order to observe chick embryo development outside the shell, we made vessels from acrylic cups and Riken wrap, a Japanese version of Saran Wrap. Fertilized eggs were incubated within their shells for 56 hours, then transferred into the vessels and incubated for a further 7 ½ days at 39°C with high humidity (total time of 10 days). To observe and later compare ex ovo development of chicks, control eggs were left to be incubated within their shells to develop normally. Afterwards, the embryos were removed and fixed in paraformaldehyde, stained with alcian blue and alizarin red, and cleared in glycerin. During incubation the vessels or eggs were rotated or turned at least twice daily to prevent the yolk from sticking to the shell’s surface.
