William Howard Stein, in partnership with Stanford Moore, was a pioneer in the field of protein chemistry. Although other scientists had previously established that proteins could play such roles as that of enzymes, antibodies, hormones, and oxygen carriers, almost nothing was known of their chemical makeup. Stein and Moore, during some forty years of collaboration, were not only able to provide information about the inner workings of protein molecules, but also invented the mechanical means by which that information could be extracted. Their discovery of how protein amino acids function was accomplished through a study of ribonuclease (RNase), a pancreatic enzyme that assists in the digestion of food by catalyzing the breakdown of nucleic acids. But their work could not have been accomplished without the development of a technology to assist them in collecting and separating the amino acids contained in ribonuclease. Their invention of the fraction collector...