2I 4 



ESSENTIALS OF BACTERIOLOGY 

 WASSERMANN SCHEME 



Noguchi modification of the Wassermann reaction 



consists in using human corpuscles and antihuman ambocep- 

 tor, and, as antigen, acetone insoluble lipoids. 



Antigen. Extract a finely ground ox-heart with 10 vol- 

 umes of absolute alcohol at 37 C. for several days; filter 

 and evaporate the extract (using an electric fan and not heat) 

 almost to dryness. Extract the residue with ether; decant, 

 evaporate the ether, and redissolve in the smallest quantity of 

 pure water-free ether. To this ethereal solution add 5 

 volumes of water-free acetone. A precipitate forms which 

 is the antigen. The precipitate is dissolved in purest methyl- 

 alcohol in the proportion of 3 per cent. For use, i c.c. of 

 this alcoholic solution is mixed with 9 c.c. of salt solution. 



Titration of Antigen. (i) Hemolytic Action. A tube con- 



