The specificity of serological reactions / [Karl Landsteiner].

  • Karl Landsteiner
Date:
1936
Catalogue details

Licence: In copyright

Credit: The specificity of serological reactions / [Karl Landsteiner]. Source: Wellcome Collection.

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    many important biochemical phenomena, such as enzyme re- actions and pharmacological and chemotherapeutic effects.7 The term “specificity” is often used to imply that a certain immune serum reacts with only one of many biologically similar substances, as tetanus antitoxin with no other toxin but that produced by B. tetani. However, it is known for instance that snake8 antivenins may neutralize not only the venom used for immunization but also to some degree venoms from other snakes or the scorpion and, as has already been pointed out, the selectivity is not absolute when proteins or cells of related origin are tested with an immune serum; indeed it will be seen later that, using chemically well defined compounds, overlapping re- actions occur regularly, provided the substances are sufficiently similar in chemical constitution. The word “specificity” then signifies that the reaction with one of the antigens, namely that used for immunization (“homologous” antigen), is stronger than with all others (“heterologous” antigens). Yet even this definition is not comprehensive enough, since it does not include a group of phenomena which resemble antibody reactions in all essentials. A case in point is that of plant haemagglutinins.9 In the seeds of Abrus precatorius and Ricinus communis, there are along with toxins (abrin, ricin) substances which clump blood cor- puscles, quite like the haemagglutinins of animal sera. Agglu- tinins of this type have also been found in numerous non- poisonous plants, particularly in Papilionaceae.10 Many of these substances, which are antigenic and presumably proteins, act in very high dilutions and upon practically all sorts of blood. However, when certain concentrations of abrin and ricin, for example, are mixed with the blood of different animals, it will be found that the reactions differ in strength; thus one of two sorts of blood may be agglutinated more intensely by abrin, 7 On selective adsorption of enzymes by inorganic substances, see Will- statter (2), Waldschmidt-Leitz (3); on the specific action of dyes on enzymes, see Quastel (4). 8 See (4a), v. (26). 9 Robert (5), v. Schiff (6). 10 Landsteiner and Raubitschek (7), v. Eisler (8), Mendel (9), Robert (10).
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