Conglutination

CONGLUTINATION (from Latin conglutinare-to glue), a term applied to the phenomenon of gluing together various organized particles with the formation of a continuous fine-grained or homogeneous mass. Most often, C. affects erythrocytes, Bizzozero plates (blood platelets, thrombocytes) and bacteria; the active factor in individual cases of C. may be different; but the basis of this phenomenon is apparently always a sharp change in physicochemical properties, mainly surface tension of the conglutinating elements. C. of erythrocytes is most often observed in blood stasis, when erythrocytes stopped in their movement stick together and the boundaries between them disappear. C. of Bizzozero plates occurs in the process of thrombosis, playing in the latter a role of a very important factor. Finally, specifically in the doctrine of immunity, the term C. is applied to the phenomenon of gluing together of erythrocytes or microbes under the action of inactivated bovine serum in the presence of the corresponding sensitizer (amboceptor) and alexin (complement). This type of C. is demonstrated as follows: washed bovine erythrocytes are introduced into a mixture of inactivated bovine serum and fresh horse serum (alexin). In this case, no changes occur. But if the bovine erythrocytes are previously treated with immune serum against them from a rabbit, i.e., sensitized them, then under the same conditions after 10-15 minutes the erythrocytes precipitate in the form of dense clumps, and subsequently undergo hemolysis. The active principle of bovine serum was named by Bordet and Ghey (Bordet, Gay; 1906) 'bovine colloid', and by Bordet and Streng-conglutinin (1909). Conglutinin, like agglutinin and sensitizer, withstands heating to 55-60° for 1¹₂ hours, but differs in that for its fixation on the antigen, the latter must be previously sensitized and loaded with alexin (complement). As a sensitizer, one can use either the corresponding immune serum or normal bovine or horse serum. The C. reaction has found application in serodiagnosis, as it can serve as an indicator in the complement fixation reaction. It is especially often used to establish chronic glanders in horses. In addition, with the help of this reaction (Barykin; 1911), it is possible to detect the formation of a precipitate invisible to the naked eye, and in this sense the conglutination reaction finds its application both in forensic and sanitary-hygienic examinations, and in the resolution of general biological questions (genetic closeness of plants, animals, etc.).