James Edgar Till OC OOnt FRS FRSC (born August 25, 1931)[1] is a University of Toronto biophysicist, best known for demonstrating – in a partnership with Ernest McCulloch – the existence of stem cells.
He attended the University of Saskatchewan with scholarships awarded by the Standard Oil Company and the National Research Council, graduating with a B.Sc.
Harold E. Johns recruited Till to the Ontario Cancer Institute at Princess Margaret Hospital shortly after he completed his work at Yale.
In the early 1960s, McCulloch and Till started a series of experiments that involved injecting bone marrow cells into irradiated mice.
They observed that small raised lumps grew on the spleens of the mice, in proportion to the number of bone marrow cells injected.