John Jacob Abel the position of chair of the department until he retired at the age of 75 in 1932. Ever since his early years in Europe, Abel showed great interest in isolating pure form of internal gland hormones. The first work that led to his international reputation as a pharmacologist and biochemist was the isolation of epinephrine from adrenal medulla. However, he was only able to isolate a monobenzoyl derivative of epinephrine. While he was improving his processes on decomposing the benzoyl derivative to obtain salts of epinephrine using saponification, a Japanese chemist J. Takamine, who had visited his lab, was able
John Jacob Abel research on extracting insulin, on November 1925, Abel finally was able to witness one of the most beautiful sights of his life, "glistening crystals of insulin forming on the sides of a test tube". While at the California Institute of Technology, Abel completed an article in the proceedings of the National Academy of Sciences entitled "Crystalline Insulin" in 1926. Although Abel's work received great compliments from the media and the science community, some doubted the purity of his crystals as preliminary tests revealed that they were in fact proteins. The test result was contrary to the dominant view at the