A Technic for Cross-Transfusion of Blood in Embryonic Chicks and Its Effect upon Hatchability.

Abstract

A method is described by which 0.04-0.4 ml of blood may be cross-transfused in 9-18 day old chick embryos with almost no increase in mortality over untreated control eggs. Of the 567 eggs tested, 82% hatched, as compared to 87% of the control eggs. By presently known techniques it is difficult to hold the needle in place, and bleeding from the needle puncture leads to death especially toward the end of incubation. This is avoided by (1) clamping the needle rigidly and moving the egg on a flexible clay base onto the needle and, (2) after withdrawal and/or injection of blood, leaving the needle in the vessel firmly attached to the egg with melted paraffin. The needle is removed several days later, when the clotting mechanisms are more fully developed and when scar tissue has formed around it.