628 A MANUAL OF BACTERIOLOGY 



Front Row. 



1. 1 vol. . . Negative serum. Positive serum. 



2. 10 vols. . Comp. dil. + antigen. Comp. dil. + antigen. 



Incubate in the water- bath for twenty minutes and at the end 

 of this period add to each tube 5 volumes of the amboceptor- 

 corpuscle mixture and incubate for a further twenty to thirty 

 minutes. If all is satisfactory, at the end of this time both tubes 

 in the back row should be completely hsemolysed ; in the front 

 row, Tube 1 should be hsemolysed, but Tube 2 should show com- 

 plete fixation with no haemolysis. 



E. THE TEST. If the preceding control is satisfactory, the test 

 may now be proceeded with (refer to Sects. VI and VII, p. 620). 

 While the standardisation and control tests have been incubating, 

 the specimens to be tested may be filled into quill tubes ready for 

 the test (1 volume of serum or 2 volumes cerebro- spinal fluid). 



Presuming that tests for " positiveness " will be done 

 (Sect. VIII, p. 621), if there are only a few specimens, say up to 

 twenty, it saves time in the end to fill four quill tubes with each 

 specimen. Three tubes are then tested respectively with 2, 

 5 and 7 m.h.d. complement in the presence of antigen, and the 

 fourth tube with 2| m.h.d. complement in the presence of saline. 



If more than twenty specimens have to be tested, two quill 

 tubes may be filled with each specimen ; one is then tested with 

 2 m.h.d. complement in the presence of antigen, the other 

 similarly in the presence of saline. The specimens which are 

 positive from this preliminary test may then be tested for " posi- 

 tiveness " with 5 and 7 m.h.d. complement in the presence of 

 antigen. 



The test is done in precisely the same manner as in the control 

 test (D above). 



The amount of complement dilution -+- antigen dilution and 

 of complement dilution + saline to be made up is 0-2 c.c. for 

 every specimen and a little over, equal volumes of complement 

 dilution and of antigen dilution or saline being mixed immediately 

 before use. 



Notes on the Test 



General Remarks. Either complete fixation without any 

 haemolysis or complete haemolysis is obvious enough. Partial 

 haemolysis is also soon readily determined with the naked eye ; 



