246 MEDICAL BACTERIOLOGY 



put o.i cc. of positive serum in each of the three tubes provided for it, put o.i 

 cc. of negative serum in each of the three tubes provided for it. 



14. Put one unit of complement in all the tubes in the top and middle rows 

 and in the antigen control tube, put two units of complement in all the tubes in 

 the bottom row, except the antigen control. 



15. Shake each tube to thoroughly mix its contents and place in incubator at 

 37C. for i hour. 



1 6. Put two units of amboceptor (rabbit serum) in every tube except the 

 complement control. 



17. Put i cc. of the 5 per cent, suspension of red cells in every tube. 



1 8. Shake each tube to thoroughly mix the contents and replace in incubator 

 for i hour. 



19. Inspect each tube and record appearance, place in refrigerator or allow 

 to stand at room temperature for several hours and then make final inspection 

 and record reactions. 



INSPECTION OF THE COMPLETED WASSERMANN TEST 



When the tubes are removed from the incubator at the end of the second 

 hour of incubation the complement control tube should be inspected first. If 

 it shows hemolysis the guinea-pig serum is at fault, the results are worthless and 

 the test must be repeated with new guinea-pig serum. If it shows no hemolysis 

 the hemolytic system control tube is next inspected; this should show complete 

 hemolysis; if it does not an insufficient amount of complement or amboceptor 

 has been used, the results are therefore worthless and the test must be repeated. 

 The complement and hemolytic system controls presenting the proper appear- 

 ance, inspection of the antigen control follows. Hemolysis should be complete; 

 if it is not, an excessive quantity of antigen has been employed, the results are 

 worthless, and the test must be repeated after restandardization of the antigen 

 or the introduction of a new standardized antigen. 



When complement control, hemolytic system control, and antigen control 

 tubes all present the proper appearance, the known negative serum and known 

 positive serum controls are inspected. The tube for each of these, containing 

 no antigen, should show complete hemolysis. The other known negative tubes 

 should both show complete hemolysis. The known positive tube containing 

 one unit of complement should show no hemolysis, the other may show com- 

 plete, incomplete or no hemolysis. 



Only when all these controls are correct can one be confident that technical 

 errors are absent (see Fig. 36). 



Of the tubes containing the serum or sera under examination, those without 

 syphilitic antigen are inspected first, they must show complete hemolysis, 

 otherwise they are not susceptible to the Wassermann test. 



Next in order is inspection of the tubes containing one unit of complement. 

 If these tubes show complete hemolysis it is evidence of a negative reaction; in 

 this case the tubes containing two units of complement will also show complete 

 hemolysis. 



