Erythrocytes, blood group substances

Fortunately from the chemists point of view, there are polysaccharides with blood group activity more readily accessible than those from erythrocytes, and it is with the former that most chemical investigations have been concerned, although the relationship between these and the blood group substances proper from erythrocytes is not yet clear. Indeed the relationship may be no more than a close similarity in chemical structure of some parts of the molecular complex. 

Lactosamine and isolactosamine (lactosamine analogue with D-galactopyranose linked to A-acetyl-D-glucosamine) are a well characterized set of (7-linked oligosaccharides that make up the ABO human blood group substances [148]. They are on the surface of erythrocytes and divide human blood into four distinct types. The following core structure makes up the 0-blood type and is found in all four blood types ... 

In human biochemical genetics, a large number of biochemically or immunologically defined traits is known, so that almost every person can be demonstrated to be biochemically unique. In human blood, it is not only the blood group substances which are used for a biochemical identification but a fairly large number of enzymes as well, especially the erythrocyte enzymes. 

Koscielak, J., Gardas, A., Pacuszka, T., and Piasek, A., 1973, A, B, and H active blood-group substances of human erythrocyte membrane, in Membrane-Mediated Information, Vol. 1, Biochemical Functions (P. W. Kent, ed.), pp. 95-103, American Elsevier Publishing Co., New York. 

Liotta, I., Ouintilliani, M., Ouintiliani, L., Buzzonetti, A., and Guiliani, E., 1972, Extraction and partial purification of blood group substances A, B, and H from erythrocyte stroma. Vox Sang. 22 171. 

These specific substances or blood group factors are detected by their property of inhibiting agglutinin reactions between human erythrocytes and heterologous human sera. This is the so-called isoagglutinin test which can detect the factors in dilutions of more than 1 part in 10 million. An even more sensitive but less specific test is their power to inhibit hemolysis of sheep s erythrocytes by the serum of rabbits immunized with certain human corpuscles. 

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