A blood transfusion is a medical procedure in which compatible, cross-matched blood (red blood cells) is transfused into a person through an intravenous line (IV).
Karl Landsteiner, Austrian American immunologist and pathologist who received the 1930 Nobel Prize for Physiology or Medicine for his discovery of the major blood groups and the development of the ABO system of blood typing that has made blood transfusion a routine medical practice. After receiving