Antigen for Precipitation Test 493 



Antigen 3. Same as antigen 2, except that the alcohol ex- 

 traction was carried out in the water bath at 37.5° C. for 2 days 

 with frequent shaking. Same color index as above. 



Antigen 4. Same as Antigen 1, to which was added a second 

 alcoholic extract carried out for 2 days at incubator temperature 

 having approximately the same color range. 



Antigen 5. Ether extractives were removed in the usual man- 

 ner and dried heart muscle extracted with alcohol for three hours 

 in reflex condenser. 



Antigen 6. Ether extraction carried out for 1 hour in reflex 

 condenser, followed, after filtration and washing with fresh 

 ether and drying, by alcohol extraction also by means of a re- 

 flex condenser for 1 hour. 



Antigen 7. Dried heart muscle was extracted in 95 per cent, 

 alcohol for three days in the incubator. The alcohol was then 

 filtered off, evaporated to dryness and taken up in a small amount 

 of ether. About ten times the amount of acetone was then added, 

 permitted to stay over night, the acetone decanted and the preci- 

 pitate redissolved in absolute alcohol. (Noguchi.) 



Antigen 8. Ether extractives were removed in the usual man- 

 ner, and dried beef heart was extracted with alcohol for 3 days 

 in the incubator. After filtration, the alcohol was evaporated 

 to dryness, taken up in a small amount of ether and precipitated 

 with an excess of acetone. The precipitate was finally taken up 

 in absolute alcohol. 



Antigen 9. . Ether extract of Antigen 8 was evaporated to 

 small volume, precipitated with excess of acetone and precipitate 

 suspended in alcohol and placed in incubator overnight, filtered 

 next morning. 



Antigen 10. Equal quantities of antigens 8 and 9. 



Antigen 11. Alcoholic solution of acetone insoluble product 

 from ether extract of beef heart obtained after 1 hour extrac- 

 tion in reflex condenser. 



Antigen 12. Equal quantities of Antigens 11 and 6. 



Antigen 13. Ether extraction of dried beef heart was pre- 

 pared and saved. An alcoholic extract was then obtained, evap- 

 orated to dryness and taken up in a small amount of ether. This 

 was mixed with original ether extract and acetone insoluble 

 antigen in alcohol prepared from it. This was finally mixed 

 with a second alcoholic extract of the same dried muscle. 

 fKolmer.) 



