[4] He emigrated with his family to New York in 1923 at the age of 55 for professional opportunities, working for the Rockefeller Institute.

In 1937, with Alexander S. Wiener, he identified the Rhesus factor, thus enabling physicians to transfuse blood without endangering the patient's life.

[3] From 1891 to 1893, Landsteiner studied chemistry in Würzburg under Hermann Emil Fischer, in München, Eugen Bamberger and in Zürich under Arthur Rudolf Hantzsch.

From November 1897 to 1908 Landsteiner was an assistant at the pathological-anatomical institute of the University of Vienna under Anton Weichselbaum, where he published 75 papers, dealing with issues in serology, bacteriology, virology and pathological anatomy.

[8] From 1908 to 1920 Landsteiner was prosector at the Wilhelminenspital in Vienna and in 1911 he was sworn in as an associate professor of pathological anatomy.

During that time he discovered – in co-operation with Erwin Popper – the infectious character of poliomyelitis and isolated the polio virus.

[10] Based on his findings, the first successful blood transfusion was performed by Reuben Ottenberg at Mount Sinai Hospital in New York in 1907.

[11] After World War I, Vienna and the new republic of Austria as a whole was in a desolate economic state, a situation in which Landsteiner did not see any possibilities to carry on with his research work.

He decided to move to the Netherlands and accepted a post as prosector in the small Catholic St. Joannes de Deo hospital (now HMC Westeinde) in The Hague[12] and, in order to improve his financial situation also took a job in a small factory, producing old tuberculin (tuberculinum pristinum).

Shortly thereafter, Landsteiner and his collaborator, Philip Levine, published the work and, later that same year, the types began to be used in paternity suits.

[18] In 1916, he married Leopoldine Helene Wlasto, a Greek Orthodox woman who converted to her husband's Catholic faith.