white lineWilliam C. Rose established the essential amino acid requirements of the laboratory rat and then humans, after discovering the last of the essential amino acids to be identified, threonine.Born in South Carolina, Rose attended graduate school at Yale’s Sheffield School of Science where Russell Chittenden directed him to the lab of Lafayette Mendel, with whom he worked on his doctorate.At the University of Illinois Urbana-Champaign, where he spent most of his career, Rose demonstrated that eight amino acids were required in the human diet and thus were essential: isoleucine, leucine, tryptophan, lysine, methionine, phenylalanine, threonine, and valine.