Background
Cohn was born on December 17, 1892, in New York City, the son of Abraham and Maimie Einstein Cohn.
5801 S Ellis Ave, Chicago, IL 60637, USA
Cohn received his Ph.D. from the University of Chicago in 1917.
Cohn was born on December 17, 1892, in New York City, the son of Abraham and Maimie Einstein Cohn.
Cohn received his Ph.D. from the University of Chicago in 1917.
After taking his Ph.D. (1917) with L. J. Henderson of Harvard and F. R. Lillie of the University of Chicago, Cohn worked with T. B. Osborne in New Haven and S. P. L. Sørensen in Copenhagen. Returning to Harvard Medical School in 1920, he joined the new department of physical chemistry, then headed by Henderson (and later by Cohn himself). He initiated active research on the solubilities in different media and their acidic and basic properties. From 1926 to 1932 he also studied the factor in liver that G. R. Minot had shown to be effective against pernicious anemia. Cohn obtained a highly active preparation of great clinical use but failed to isolate the pure active principle (vitamin B-12), which was obtained by others in 1948.
About 1930 Cohn turned his attention to the amino acids and peptides, the smaller building blocks of which proteins are composed. These are extraordinarily polar molecules, containing widely separated centers of positive and negative charge. They also contain various polar and nonpolar side chains. Over a period of ten years Cohn and his associates established many systematic relations between the structures of these molecules and their physical properties - dipole moments, solubilities, apparent molal volumes, ionization constants, and infrared and Raman spectra. They showed how to describe influences of electric charge and dipole moment, and of various polar and nonpolar side chains, in quantitative terms, thus laying a foundation for the further study of proteins.
This work provided the background essential for the next major phase of Cohn’s activities, which coincided with the outbreak of World War II. Supported by the Office of Scientific Research and Development, he initiated and directed a major program, involving biochemists, clinicians, and many others, for the large-scale fractionation of human blood plasma. This yielded purified serum albumin for treatment of shock, gamma globulin for passive immunization against measles and hepatitis, fibrinogen and fibrin for neurosurgery, and numerous other protein fractions of blood plasma. The methods developed in the laboratory and its pilot plant were rapidly applied on an industrial scale, and the products were distributed for large-scale use by the armed forces and later in civilian medicine. Apart from its practical results, this program led to a great advance in knowledge of the chemistry and physiology of the multifarious components of blood plasma.
After the war the fame of this work attracted young investigators from all over the world to Cohn’s laboratory, and he continued to contribute actively to the advancement of protein chemistry until his death.
Cohn was an excellent project leader, being driven, ambitious, and extremely well organized. He also had a keen taste in people and scientific projects and could sense when either would be successful.
He was also selfless in the best (and worst) scientific tradition. For example, Cohn drove himself relentlessly and ignored his doctors' advice to cut back on working because of his high blood pressure (which finally killed him).
However, Cohn was also well known for being harsh and demanding of his subordinates, being something of a martinet.
Nothing is known of Cohn's personal life.