Karl Landsteiner

Karl Landsteiner was born on June 14, 1868, in Baden bei Wien. Graduating in medicine from the University of Vienna in 1891, Landsteiner worked at the Institute of Pathological Anatomy, conducting over 3,600 autopsies and immersing himself in the chemistry of antibodies.

In 1900, Landsteiner discovered that serum from one person often agglutinated red blood cells from another, identifying the three primary blood types (A, B, and O; AB added later). In 1908, he and Erwin Popper identified the poliovirus. Moving to the Rockefeller Institute in New York in 1922, he co-discovered the Rh blood factor. His birthday, June 14, is commemorated globally as World Blood Donor Day.