Pre‐absorption—a Valuable Tool in Serotaxonomic Work

Abstract

The resolution of unit characters in serotaxonomy is an ideal now possible using monoclonal antibodies to recognise single epitopes. Understanding of the theoretical taxonomic implications of suchdata and methods for analysing it were pioneered by Professor Otto Moritz using pre-absorbed antisera.One pre-requisite for a taxonomist is the ability to look at a complex and apparently chaotic situation, and there to find some traces of order. Serotaxonomy is fraught with difficulties, both practical and theoretical, and it is not surprising that few botanists pursue this course of investigation. It is interesting that most of those who do so are also students of ecology, another daunting discipline overwhelmed with undefinable and imponderable features. In such situations most experimental scientists prefer to limit themselves to studies which can be investigated "analytically," in which most factors can be held constant, whilst one (or at most a few) is varied. Thus erstwhile taxonomists may turn into geneticists; ecologists into physiologists, and any immunologist or protein chemist would shrink from the complex situations studied by serotaxonomists.In the early days of serology there was little knowledge of the identity and structure of proteins and other antigenic components, but the precipitin reaction was observed as a phenomenon, and its taxonomic implications were soon appreciated. Immunisation of a host animal with an antigen system, such as a plant extract, could elicit the production of (i.e. generate) an antibody system or antiserum: antigen system and antibody system could react together in vitro to produce a visible precipitate: most precipitate was produced by an antibody system with its reference antigen system, less precipitate with other crossreacting antigen systems: the amount of precipitate indicated the affinity of the crossreacting antigen system to the reference antigen system.Early this century the investigations at Konigsberg and Berlin in Germany brought first fame, then infamy to phytoserology (Chester, 1937; Moritz, 1958), but fortunately, as a young medical student, Moritz (1928) became embroiled in the controversy and then took the torch and led the way for the next 50 years. He maintained interest in phytoserology, and critically and painstakingly improved on both method and theory (Moritz, 1929(Moritz, , 1931(Moritz, , 1932(Moritz, , 1934(Moritz, , 1956(Moritz, , 1958(Moritz, , 1965.Modern knowledge of protein synthesis and the genetic code has revolutionised our understanding of the taxonomic characters presented by proteins, likewise immunology has been revitalised by new knowledge and understanding of the production and structure of antibodies. Paradoxically, these developments have done little to simplify or alleviate the fundamental problems in phytoserology.Probably the greatest contribution of numerical taxonomy is the discipline of defining the unit character. Long ago Moritz and Jensen (1961) initiated definition of unit characters and other concepts in phytoserology. ...