In 1901, Austrian American immunologist and pathologist while mixing blood of different people made a groundbreaking discovery saving numerous lives and helping the world in creating blood banks, enabling modern surgery and advancing several other fields

In 1901, Austrian American immunologist and pathologist made a groundbreaking discovery while mixing blood of different people. The discovery saved numerous lives and helped the world in creating blood banks, enabling modern surgery and advancing several other fields. Karl Landsteiner identified human blood groups, helping doctors understand transfusion reactions and making compatible blood transfusions possible.