WASSERMANN'S REACTION 739 



and so fix the hsemolytic complement." There is simply an increase in the 

 body fluids of substances already present though in smaller quantity in 

 normal serum ; proof of this is afforded by the fact that normal serum used 

 in large doses will give Wassermann's reaction. 



The serum-reaction in syphilis is, however, notwithstanding the theories 

 advanced in explanation of the phenomenon, frequently used as a practical 

 method for the diagnosis of syphilis. The experiments summarized above 

 have much simplified the technique of the reaction and a purely chemical 

 test depending solely upon the precipitation or non-precipitation of the serum 

 in presence of certain substances and especially of bile salts has been devised. 



Space will not allow a description of all the modifications of Wassermann's 

 method which have been introduced ; his original method therefore, and the 

 methods based upon a chemical reaction which, by reason of their simplicity, 

 are now at the disposal of all medical men, will alone be described. 



Wassermann's technique for the serum-diagnosis of syphilis. 



The ordinary reagents used in the Bordet-Gengou reaction are necessary 

 for the serum-diagnosis of syphilis. 



I. Antigen. -Wassermann used an extract of the liver of a newly-born 

 congenitally syphilitic infant. An extract of the liver of a newly-born non- 

 syphilitic infant serves the purpose equally well. 



(a) A portion of the liver, which must be fresh and have been collected 

 with all precautions to avoid contamination, is ground up very finely with a 

 very small quantity of sterile normal saline solution in a Borrel's mincer or 

 in an agate mortar. The emulsion is poured into Petri dishes and dried in 

 vacuo over sulphuric acid. The dried contents of the Petri dishes are col- 

 lected and ground up in a pepper mill. The brown powder is sifted and stored 

 in the dark in absolutely dry, well-stoppered bottles. 



When required for use, take 1 gram of the powder and triturate it in an 

 agate mortar with 25 c.c. of normal saline solution. Leave the emulsion to 

 stand for 10 hours in the ice chest, centrifuge and use the supernatant liquid 

 as the antigen. 



(6) An alcoholic extract of the liver may be used (Landsteiner). One part 

 of the dried and powdered liver is placed in a stoppered bottle with 30 parts 

 of absolute alcohol. Leave for 2 days shaking frequently and then filter 

 through paper. For use, dilute this extract with ten times its volume of 

 water. 



In the same way, an extract of fresh liver can be made by macerating 10 

 grams of ground up liver in 100 grams of absolute alcohol. 



(c) Levaditi and Yamanouchi, instead of extract of liver, use the following 

 solution : 



Taurocholate or glycocholate of sodium, 1 gram. 



Normal saline solution, - 100 grams. 



Carbolic acid, - 0'50 gram. 



However prepared, the antigen must be carefully titrated before being 

 used. For this purpose the experiment will be arranged as described on p. 

 235, using quantities of 0*05 c.c., O'l c.c., 0'2 c.c., 0'3 c.c., 0'4 c.c., and ! 5 c.c., 

 of liver extract. In the subsequent experiments the smallest quantity of 

 antigen which will give complete haemolysis is used (0*2 c.c., for example). 



II. Suspected serum (anti-body). -The patient's serum collected with the 

 aid of a Bier's cupping glass or by puncturing a vein at the bend of the elbow, 

 is left to coagulate. The serum is then separated and heated (inactivated) 

 for half an hour at 55-56 C. It also must be titrated in the usual manner 

 (p. 236) 



