14 QUATERCENTENARY STUDIES IN PATHOLOGY 



It was evident from these figures as well as from many similar results 

 that a great destruction of the normal " opsonin " took place at 55° C. 



Again the unheated blood serum of the eel is strongly haemolytic for 

 most red blood cells, yet, when heated, it appears to exert no opsonic 

 effect on red blood cells for which it is haemolytic. It is impossible to 

 perform phagocytic tests with eel's serum in the unheated condition, 

 since it is markedly toxic for leucocytes, and, by dissolving these, 

 renders such tests futile. 



Example, — An eel's serum, of which when unheated '05 cc. produced 

 almost complete haemolysis of 2 cc, of a 10 % suspension of guinea-pig 

 corpuscles, after 2\ hours at ly"" C, was used. Such a serum when 

 heated no longer produced haemolysis, nor had it any power of producing 

 phagocytosis of the red blood cells of the guinea-pig when tested in the 

 usual way. In films in which 100 polymorphonuclears were enumerated 

 none contained any red cells, although we may assume that haemolytic 

 amboceptor was present in a very large amount. 



In diluted immune sera the haemolytic amboceptor may be present, 

 but without being able to render the corresponding red cells suitable for 

 phagocytosis. 



Experiment. — Into two series of suitable test tubes 'Oi, "005, '003, '002 

 cc. of the immune rabbit's serum was placed. To each tube was added 

 2 cc. of a 5 7o suspension of the washed red cells of the ox, and all were 

 made up to equal volumes with '85 saline solution. One series was 

 complemented with fresh normal guinea-pig serum, the other being left 

 uncomplemented. The immune serum was present in the mixtures in 

 the proportions of I in 220, i in 450, i in 730, and i in 1 100 respectively. 

 A control consisted of a similar mixture containing the serum in the 

 proportion of i in 10. All the mixtures were placed for 2 hours at 37° 

 C. At the end of that time the following results were noted : — 



Amount of serum. Complemented series. Uncomplemented series. 



•01 CC. Haemolysis almost complete. No haemolysis. 



•005 cc. M marked. n 



•003 cc. II slight. II 



•002 cc. II slight. I! 



The tubes of the uncomplemented series and the control were then 

 well shaken up and centrifugalised. The supernatant fluid was pipetted 

 off, and replaced by normal saline solution. This was repeated thrioe. 



(314) 



