Charles joined the Department in 1968 as an assistant professor and became professor in 1980. His main research focus was how proteins that transport Na and small molecules are organized in epithelial tissues and the retina. Studies of note are the membrane defect in the genetic decease "Glucose-Galactose Malabsorption", the role of the Na pump in secretory epithelia. The relative distribution of the Na pump in the kidney and the origin of the "dark current" in vertebrate photoreceptors. His teaching encompassed graduate, medical, dental and nursing students. His present interest is in developing "web based" teaching material for selective subjects in physiology.