INTRODUCTORY 3 



concerned, owing to the visible effect produced on the 

 corpuscles, can be studied with an exactitude in the case of 

 haemolysis which is impossible in the case of other sera 

 hence the importance of the study. The facts ascertained 

 can then be tested in the case of anti-bacterial sera. 

 It may be stated that while numerous striking analogies 

 have been proved to obtain between these two chief kinds 

 of sera, important differences are also brought out. The 

 properties of the three classes of molecules concerned in 

 haemolysis by an anti-serum will be considered in turn. 



METHOD OF PRODUCTION OF HJEMOLYTIC SERA AND 

 ESTIMATION OF DOSAGE 



The development of a haemolytic serum is usually a matter 

 of comparative simplicity. It is sufficient to inject quantities 

 of the red corpuscles at suitable intervals. In all cases 

 the corpuscles ought to be washed several times in salt 

 solution, in order to free them from the serum ; otherwise 

 serum anti-substances will be developed and a complication 

 may be introduced. Rabbits have been chiefly used in 

 our experiments, and the corpuscles have been injected 

 intraperitoneally. In the case of ox corpuscles, injections 

 of 5, 10, and 15 c.c. respectively, with intervals of ten days 

 between, usually result in the production of a potent serum. 

 The haemolytic action reaches its maximum from seven to 

 ten days after the last injection. Accordingly, a pre- 

 liminary test should be made at this time, and if the result 

 is satisfactory, the animal should be killed by bleeding. 

 The blood is collected with aseptic precautions; the 

 serum is allowed to separate, arid is conveniently stored in 

 glass tubes, sealed at the ends. It is advisable to expose 

 these to a temperature of 55 C. for an hour on three succes- 

 sive days to ensure sterility. Immune-body is relatively a 



B2 



