Also: Landsteiner, "Ueber Agglutinationsercheinungen normalen menschlichen Blutes," Wiener klinische Wochenschrift, 14, 1901, 1132-1134.

Landsteiner discovered that human blood contains iso-agglutinins capable of agglutinating other human red blood cells. He first mentioned this chance discovery in a footnote to the above paper published in 1900. In the following paper published in 1901 he proved that this agglutination was not the result of a disease process, but was demonstrable in the serum of healthy individuals. Furthermore, he was able to show that each serum can agglutinate the red cells only of certain other individuals. He found that the sera could be divided into three distinct groups: group A agglutinates the red cells of group B, but not those of group A; group B agglutinates the red cells of group A, but not those of group B; and group C agglutinates both and B red cells, but is not agglutinated by the sera of either group A or group B.
He divided human blood into three groups (A, B, and O, which he called A, B, C).

1930 Landsteiner was awarded the Nobel Prize for Physiology or Medicine "for his discovery of human blood groups."

(Thanks to Juan Weiss for the reference to Landsteiner's 1901 paper and its interpretation.)

The first description of an auto-antibody, and of an auto-immune disease, paroxysmal cold hemoglobinuria. See A.M. Silverstein, A history of immunology, New York, Academic Press, 1989, Ch. 8, The Donanth-Landsteiner autoantibody…English translation in Bibel, Milestones in immunology, (1988).

Dark field method of diagnosis for presence of T. pallidum.

Landsteiner and Popper were the first to isolate poliovirus and to transmit poliomyelitis to monkeys.

Serum from a monkey that had recovered from experimental poliomyelitis was mixed with an emulsion containing active polio virus; it failed to produce paralytic disease when injected into fresh monkeys.

Discovery of M and N agglutinogens. See also the same journal, pp. 941-42.

Summary of many years of research on antigen-antibody interactions. Landsteiner considered his study of hapten-antibody reactions to be his most significant work. Revised English translation, 1936 (revised 1945).

Recognition of the Rh antigen

Cellular transfer of delayed hypersensitivity, establishing the criticial role of mononuclear cells in cellular immunity.