A method to increase the survival rate of early chick embryos in experiments involving surgical intervention

A method is presented by which the survival rate of early chick embryos following surgical procedure can be greatly improved. It was discovered that the embryos were dying at the stage of the operating procedure at which ink was being introduced under the embryo. Ink was used to visualize the embryonic features more easily. The use of a contrast medium in which the ink has been previously mixed with yolk in the ratio of 1:30 solved the problem.