WASSERMANN AND OTHER COMPLEMENT FIXATION TESTS 249 



Should inspection reveal complete hemolysis in all the tubes in the top row, 

 and no hemolysis in all the tubes in the bottom row, each of the various amounts 

 of extract used are antigenic and the extract is apparently a good one. But 

 these were not a sufficient number of tubes to show the smallest quantity that 

 is antigenic nor the smallest quantity that is anticomplementary, hence the test 

 must be extended. 



Make a 1:100 dilution by mixing 0.2 cc. of the alcoholic extract with 19.8 

 cc. of normal salt solution. 



Repeat the test exactly as before, except that the 1:100 dilution is used 

 instead of the 1:10; this in practically all cases will show the smallest amount 

 that is antigenic. Amounts of extract less than the minimum antigenic quan- 

 tity will show complete hemolysis in the tubes containing non-syphilitic serum 

 and will also show more or less hemolysis in tubes containing syphilitic serum. 



The smallest anticomplementary quantity is yet to be determined; for this 

 purpose repeat the test, using a i : 5 dilution of the alcoholic extract in quantities 

 from 0.5 cc. in the first tubes to 1.6 in the last tube. Quantities that are anti- 

 complementary show no hemolysis in the tubes containing syphilitic serum and 

 incomplete, partial or no hemolysis in tubes containing non-syphilitic serum. 

 The quantity of antigen to be used in making Wassermann tests the unit of 

 antigen has been discussed on page 244. 



When standardizing antigen, as a control, Wassermann tests are made on 

 the human sera used in the standardization, and these tests are carried out with 

 the antigen previously in use. 



SPINAL FLUID 



In certain cases it is desirable to subject the spinal fluid to the Wassermann 

 test. The fluid is obtained when the patient is in bed, lying on his side with the 

 body bent forward and thighs flexed. Under strict aseptic precautions (after 

 local anesthesia if desired) a strong needle, at least 6 inches long, is thrust be- 

 tween the third and fourth lumbar vertebrae into the spinal canal. As the 

 fluid comes out, drop by drop, it is caught in a test-tube until 5 cc. have been col- 

 lected; the needle is then withdrawn, the puncture painted with tincture of 

 iodine and covered with a sterile dressing. It is best for the patient to remain 

 at rest in bed for at least several hours. In the absence of diseases other than 

 syphilis the gross appearance of the spinal fluid is practically normal clear, 

 almost colorless and like water. Should it show any turbidity it is well, if not 

 necessary, to centrifugalize it. Spinal fluid, like blood serum, should be pro- 

 tected from contamination, examined if possible within 48 hours after its removal 

 from the patient, and inactivated by heating in a water bath at 55C. for J^ 

 hour before testing. 



The technique is the same when making a Wassermann test with spinal 

 fluid as with blood serum, except that six tubes are used each of which contains 

 one unit of complement and the first two tubes each contain o.i cc. of spinal 

 fluid, the third tube 0.2 cc. of spinal fluid, the fourth tube 0.3 cc. of spinal fluid, 



