UC Davis

The injection replication procedure has been modified for study of the thin and very delicate blood vessels of young embryos. Batson's corrosion compound (a polyester resin) modified for rapid polymerization (20:3.0:0.25, monomer: catalyst: promoter) was effective in replicating even very small blood vessels without excessive distension. Since injection of plastic induced violent heart spasms with eventual expulsion of plastic from the ventricular lumen, contractility of the heart was inhibited by injection of a 2% (w/v) aqueous solution of KNO3 prior to injection with polyester resin. Following polymerization of the injected resin, the tissues were macerated and removed, leaving a solid three‐dimensional cast of the lumen of the circulatory system. The casts were photographed with the scanning electron microscope to produce accurate micrographs for study of the developmental anatomy of the circulatory system. 1974 Blackwell Science Ltd