Blood type namely group A, group B, and group C. He defined that group A blood agglutinates with group B, but never with its own type. Similarly, group B blood agglutinates with group A. Group C blood is different in that it agglutinates with both A and B. This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930. (C was later renamed to O after the German "Ohne", meaning without, or zero, or null.) The group AB was discovered a year later by Landsteiner's students Adriano Sturli, and Alfred von Decastello.
Blood transfusion immunological reaction occurs when the receiver of a blood transfusion has antibodies against the donor blood cells. The destruction of red blood cells releases free hemoglobin into the bloodstream, which can have fatal consequences. Landsteiner's work made it possible to determine blood group and allowed a way for blood transfusions to be carried out much more safely. For this discovery he was awarded the Nobel Prize in Physiology and Medicine in 1930, and many other blood groups have been discovered since. George Washington Crile is credited with performing the first surgery using a direct blood transfusion in 1906 at St.