318 



MATSUZIRO TAKENOUCHI 



b. Test of the antithymus serum in vitro 



1 . Precipitin reaction. For the precipitin reaction, we followed 

 the procedure given by Ricketts and Rothstein ('03) for the 

 action of neurotoxic serum. They used for their precipitin 

 reaction an emulsion of nervous tissue as a precipitinogen 

 (antigen). 



Different precipitinogens (antigens) from different kinds of 

 tissue were prepared in the following manner: 



Weighed tissue, first washed with saline solution, was ground 

 thoroughly, emulsified with sterile saline solution and shaken six 

 hours at room temperature, with preliminary carbolization for the 

 purpose of avoiding bacterial contamination and alterations in 

 composition. Then it was strained through sterile cotton gauze. 

 The strained emulsion was centrifuged for a long time at high 

 speed to free the supernatant fluid from macroscopic particles. 

 The supernatant fluid was diluted again with sterile saline solu- 

 tion and carbolized. The following tissues were prepared in this 

 way. 



Weight (grams) 



Salt solution added in grinding (cc.) 



Salt solution added to the supernatant fluid 

 (cc.) 



Kidney Spleen Testes Brain ^^^^ 



2.75 

 15.0 



30.0 



0.842 

 5.0 



10.0 



0.742 

 5.0 



10.0 



1.500 

 10.0 



20.0 



0.899 

 5.0 



15.0 



To six test-tubes each containing 1 cc. of the diluted extract 

 there were added from one to five drops of serum, the sixth test- 

 tube being held as control. The quantity of the liquid in each 

 test-tube was made the same with saline solution. The tubes were 

 then put into the ice-box for sixteen to eighteen hours, avoiding 

 any evaporation. The first reading was made after four to six 

 hours and the second sixteen to eighteen hours later (table 2). 



Control tests with normal rabbit serum give a little precipi- 

 tation in some tubes, but this is slight and inconspicuous in 

 others. 



