McLean moved to
Baltimore following his graduation from the
University of California before receiving an acceptance from
Johns Hopkins School of Medicine. Following his move he was informed of a vacancy at the school and began his medical studies in 1915. McLean entered
Johns Hopkins School of Medicine in 1915 where he met and began work with physiologist
William Henry Howell. Howell admitted McLean into his laboratory and assigned him the task of investigating if an impurity was the cause of the pro-coagulating effect of
cephalin or if cephalin itself had a naturally pro-coagulating effect and to compare it to other phosphatides. This anti-coagulant was first isolated from the liver tissue of canines, which is how Heparin got its name(
hepar or "ήπαρ" is Greek for "liver";
hepar +
-in), first coined in 1918. Following the departure of McLean, Howell continued his work and with the assistance of T. Emmett Holt he isolated a water-soluble
polysaccharide anticoagulant. Howell also coined 'heparin' as the name of this compound despite being different from the compound previously discovered by McLean. McLean graduated from Johns Hopkins in 1919 and began an internship at the Johns Hopkins Hospital. McLean stayed in
Baltimore until 1924 when returned to his alma-mater, the University of California to become an instructor in surgery. After three years in California, McLean took a position in the Department of Pathology at
Cornell University, a position which he held until 1939. After leaving Cornell, McLean moved to
Columbus, Ohio, where he worked in private surgical practice and was appointed as an associate professor of surgery at Ohio State medical school. In 1949, he was appointed director of Radiation Therapy and Consultant in Malignant Diseases in
Savannah, Georgia, where he remained until his death in 1957, aged 67 years. 6 years after McLean passed away he was awarded a plaque by the
Upjohn Company to Johns Hopkins School of Medicine for his work in the discovery of heparin as a second-year medical student. ==References==