Karl Landsteiner ("tuberculinum prestinum"). He also published a number of papers, five of them being published in Dutch by the Royal Academy of Sciences. Yet working conditions proved to be not much better than in post-war Vienna. So Landsteiner accepted the invitation that reached him from New York, initiated by Simon Flexner, who was familiar with Landsteiner's work, to work for the Rockefeller Institute. He arrived there with his family in the spring of 1923. Throughout the 1920s Landsteiner worked on the problems of immunity and allergy. In 1927 he discovered new blood groups: M, N and P, refining the work he
Karl Landsteiner of these achievements. For his pioneering work, he is recognized as the father of transfusion medicine. 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 MCH Westeinde) in The Hague and, in order to improve his financial situation also took a job in a small factory, producing old tuberculin