A Quantitative Analysis of Hemagglutination and Hemolysis

Summary and Conclusions The agglutination of red blood cells of man or dog with agglutinating serum on a hemacytometer slide permits fairly accurate quantitative studies of hemagglutination and hemolysis. Under the conditions of the experiments, the maximum agglutination of the red blood cells of dogs with agglutinating serum is reached in two to four hours, in man in about twenty-four hours at 18° to 20°C. In preparations with too few corpuscles in proportion to the serum, hemolysis is well under way before the maximum agglutination is reached, unless the temperature is very low. The same was true when too many corpuscles were present. This is at least one factor in the occurrence of “inhibition zones.” The higher the temperature, the more rapid the agglutination, and the more rapid hemolysis. The secondary separation of cells at the higher temperatures accounts for the impression of greater agglutination at lower temperatures. There is very little difference in the rate of agglutination when the corpuscles are suspended in saline-citrate solution or in serum. The latter delays hemolysis somewhat. There is practically no difference in the rate and completeness of agglutination if the corpuscle suspension is acid or alkaline. Hemolysis is more rapid in the former. With an acid serum the rate of agglutination was slightly slower than with the alkaline serum, but the maximum agglutination is the same. The processes of defibrination or of washing corpuscles until they are serum-free changes the composition of the red blood cells so that a greater proportion of cells do not agglutinate. Crenation delays agglutination, but the maximum amount is the same as in control preparations. The red cells which are most resistant to the serum hemolysis are those containing nuclei, reticulum, stippling or intracellular refractive granules (including Heintz bodies, Howell-Jolly bodies and others). Cup-shaped red blood corpuscles in the preparations studied are formed by the hemolysis of one of two red cells in apposition.