[Quantitative and thermodynamic study of B antigen in a family including individuals with phenotypes B 3 and AB 3]. / Etude quantitative et thermodynamique de l'antigène B dans une famille comportant des sujets de phénotype B3 et AB3.

Four B3 and one A1B3 erythrocyte samples belonging to the same family were studied using several series of quantitative measurements: percentage of agglutination, agglutination kinetics and thermodynamic methods. For this last assay the erythrocytes were used fresh and after treatment by formalin. From the obtained results evidence was given that while B antigen density was lower in A1B3 than in B3O cells, the reactive structure is qualitatively the same in these two kinds of cells. The enthalpy change of the reaction of this B3 antigen with a non stimulated anti-B from A1O individual was -- 5,000 cal/mole, i.e. weaker than when normal B cells were concerned (-- 16,000 cal/mole).