Karl Landsteiner

Born in Vienna, Austria in 1868, Karl Landsteiner made many of the key discoveries in relation to antigens and antigenicity. Thus in the 1920's he discovered haptens and in a series of elegant experiemtns showed the remarkable specificity of antibodies for antigens. Landsteiner also discovered blood groups, the antigenic molecules located on the surface of red blood cells. He showed that these acted as antigens following incompatabile blood transfusions. This discovery finally permitted blood transfusions to be made safely and as a resulte transformed modern surgery. He was awarded the Nobel Prize in Mrdicine in 1930 for his discovery of blood groups