AN INVESTIGATION OF THE QUANTITATIVE RELA- 

 TIONSHIPS BETWEEN AGGLUTININ, AGGLU- 

 TINOID AND AGGLUTINABLE SUBSTANCE. 



By Y. K. Ohno. 1 



(From the Serum Division, Biological Laboratory, Bureau of Science, 

 Manila, P. I.) 



This article is a summary of an extensive piece of experimental work 

 conducted for the last two years as a continuation of previous studies 

 entitled "Equation of Curves and the Agglutination Phenomenon" (read 

 before the Annual Meeting of the Association for Medical Research, 

 March 24, 1905), and "The Relation between Agglutinin and Bacterio- 

 lysin" (read before the Section of Bacteriology, Hygiene and Infectious 

 Diseases, Japanese Medical Congress, Tokyo, March 4, 1906). After 

 numerous preliminary studies the attempt was made to determine the 

 law governing the mechanism of agglutination by the employment of 

 physico-chemical methods, and formula? were established which expressed 

 with exactness the quantitative reactions occurring between agglutinin, 

 agglutinoid and agglutinable substance. 



The preliminary studies established an exact technique. A bacterial 

 suspension was used of which the dose constantly employed, (0.5 cubic 

 centimeter) contained 0.5 milligram of bacteria by weight. Each test 

 tube in every experiment contained a constant volume of 2 cubic centi- 

 meters. 2 The bacterial emulsion was made from 24-hour agar slant . 

 cultures killed by the addition of 1 per cent formalin. It was found 

 that the dead cultures registered more exactly the limits of agglutination 

 than living ones. The experiments were performed with B. typhosus, 

 B. dy sentence, B. paratyphosus, B. coli, B. pyocyaneus, V. cholera, Me- 

 ningococcus intracellularis , and Staphylococcus pyogenes aureus, together 

 with corresponding immune sera. In performing the agglutination 

 experiments the various dilutions were prepared, placed in the incu- 

 bator at 37° C. and allowed to stand for twenty-four hours. The 



1 Read at the Fourth Annual Meeting of the Philippine Islands Medical Asso- 

 ciation at Manila, P. I., on March 2, 1907. 



= Which each test tube contains 0.5 milligram of bacteria. 



47 



