the credit for making blood transfusion a routine medical practice goes to Karl Landsteiner. An Austrian-American immunologist, he won the Nobel Prize for Medicine in 1930. Landsteiner lost his father at the age of 6. His mother took his custody, and supported his education. He studied medicine at Vienna University, graduating at 23.
A paper on the Influence of Diet on the Composition of Blood Ash was published in 1891. To enhance his knowledge on chemistry, he worked in a laboratory in Zurich for five years. He eventually resumed his medical studies at a general hospital in Vienna, playing the role of an assistant in pathology anatomy at Vienna University from 1898 to 1908. During this phase, he worked on morbid physiology. The ABO blood groups were identified by Landsteiner in 1901. He discovered antigens and antibodies in blood, which result in clumping of red cells, when they are added to another type.