Who discovered blood groups?

Karl Landsteiner will always be honored for his discovery of blood groups. In 1901, he showed that transfusions between individuals of like blood groups (A to A, B to B) do not result in the destruction of blood cells. Transfused red blood cells and the patient’s own red blood cells destroy each other only when they are of different blood groups. In 1901-1903, Landsteiner suggested that because the characteristics that determine the blood groups are inherited, the blood groups may be used to decide instances of doubtful paternity. In 1939, hematologist Philip Levine first explained the existence of another antigen (a substance that induces antibody production), in addition to A and B antigens, on the surface of human red blood cells. Landsteiner and hematologist Alexander Wiener dubbed the antigen “Rh (rhesus).”