In his biography on the Nobel Prize website it is stated that until the end of his life, Landsteiner continued to study the blood groups and the chemistry of antigens, antibodies and other immunological factors acting in the blood. In this way he contributed to the use of chemistry in the service of serology

Karl Landsteiner (1868-1943 Karl Landsteiner) Austrian biologist and doctor was born today 148 years ago in Vienna.
In 1930, he won the Nobel Prize for Medicine for developing a method for mapping blood types with the help of identifying clotting factors in the blood, thereby actually determining the blood types we know today. During his professional life he published groundbreaking articles in the fields of pathological anatomy, immunology and histology.
In 1937, Landsteiner discovered the RH factor, the protein component found in red blood cells, a substance that triggers an immune response that causes the formation of antibodies. Three years after his death, he received the Lasker Prize for this discovery, which some call the "American Nobel Prize."
"Karl Landsteiner was born in Vienna on June 14, 1868 (to Jewish parents, who later converted to Christianity). His father, Leopold Landsteiner, a doctor of law, was a publisher and journalist who died when Karl was six years old. Karl was raised by his mother, Fanny Hess, whom he admired and who Her death hung in his office until his death.
In 1891, Landsteiner began studying medicine at the University of Vienna. Already while he was a student, he engaged in biochemical research and in the same year 1891 he published an article on the effect of nutrition on blood composition. To gain more knowledge of chemistry he spent the next five years in the laboratories of Hentzlich in Zurich, Emil Fischer in Wurzburg and Anton Bamberger in Munich.
Upon his return to Vienna, Landsteiner resumed his medical studies at the Vienna General Hospital. In 1896 he was Max von Gruber's assistant at the Hygiene Institute in Vienna. Even in those days he was interested in the mechanisms of immunity and the nature of antibodies. From 1898 to 1908 he served as a research assistant in the Department of Pathology and Anatomy at the University of Vienna under the leadership of Prof. Anton Weichselbaum who discovered the bacterial cause of meningitis and in collaboration with Karl Frankl discovered the pneumococcus.
Because Landsteiner worked on the physiology of disease and not on anatomy, he was criticized by other researchers at this institute. In 1908, Weichselbaum secured his appointment as a forensic medicine researcher at the Wilhelminaspital in Vienna, where he remained until 1919. At the same time, he was appointed as a professor of pathological anatomy at the University of Vienna, but without salary.
By 1919, during twenty years of work on pathological anatomy, Landsteiner published in collaboration with colleagues many articles on his findings about the anatomy of diseases and immunology. He discovered new facts about the immunology of syphilis, added to our knowledge of the Wasserman reaction (which was used to test and diagnose syphilis) and discovered an immunological factor that he called the hapten - which today we know is a small molecule which together with a larger carrier such as a protein can cause for the production of antibodies that specifically bind to it. He also contributed to our knowledge about hemoglobinuria (haemoglobinuria, hemoglobin in the urine).
Landsteiner also showed that the cause of polio can be transmitted to monkeys by injecting a substance prepared by grinding parts of the spines of children who had died of this disease. In the absence of monkeys in Vienna for further experiments, Landsteiner moved to the Pasteur Institute in Paris, where monkeys were available. His work there, in addition to the independent research of Flexner and Lewis, lays the foundations for our knowledge of the cause of polio and the immunology of this disease.
Landsteiner made many contributions to the fields of anatomy, histology, and pathological immunology, in all of which Landsteiner showed not only a careful description of the observations but also an understanding of the biology behind them. But his name will always be associated with his 1901 discovery of blood groups, for which he received the Nobel Prize in Physiology or Medicine in 1930.
In 1875, the biochemist Leonard Landau reported that when a person received transfusions of the blood of other animals, these foreign blood cells were attacked when introduced into the human body. Landsteiner pointed out that a similar reaction may also occur when the transfusion originates from the blood of another person and that this is the cause of diseases such as shock, jaundice and hemoglobinuria after following up on early attempts at blood transfusions.
His hypothesis received little attention until in 1909 he classified human blood into the types we know today as A, B, AB and O. He showed that a transfusion between individuals of groups A or B (respectively) would not cause the destruction of the new blood cells and that this catastrophe only occurs when a person receives a transfusion of blood from a person who belonged to another group.
Earlier, in 1901-1903, Landsteiner suggested that the characteristics that determine blood groups are inherited, and that this characteristic could be used to determine paternity.
A large part of his and his students' work on blood groups was not done in Vienna but in New York because the working conditions there were difficult. He saw no future in Austria.
He worked at the Catholic Children's Hospital in Hag. There, between 1919-1922, he published twelve articles on the new haptens he had discovered.
His work in the Netherlands came to an end when he was offered a position at the Rockefeller Institute for Medical Research in New York and he moved there with his family. There, in collaboration with Levin Wiener, he continued his work on the blood groups which led to the expansion of the number of groups and in the research of bleeding in newborns which led to the discovery he discovered the Rh, which is also known to be part of the blood type definition today.
Until the end of his life, Landsteiner continued to study blood groups and the chemistry of antigens, antibodies and other immunological factors acting in the blood. In this way he contributed to the use of chemistry in the service of serology.
In 1939 he retired and became professor emeritus at the Rockefeller Institute, but continued to work as vigorously as before, eagerly keeping in touch with the progress of science. Indeed he died with a hand pipette. On June 24, 1943, he suffered a heart attack in his laboratory and died two days later in the hospital of the institute where he had done such distinguished work.
Landsteiner married in 1916 Helene and Letso and they had a son, who also worked in the field of medicine.