In addition to the laboratory, Macleod provided experimental animals and his student Charles Herbert Best, who worked as a demonstrator.
=== Frederick Banting in odkritje insulina ===Konec leta 1920 je z njim navezal stik mlad kanadski zdravnik Frederick Grant Banting, ki se je domislil, da bi zdravil sladkorno bolezen z ekstraktom odmrle trebušne slinavke.