114 LABORATORY COURSE IN SERUM STUDY 



SIMPLE ALCOHOLIC EXTRACT OF HEART MUSCLE 



Human, guinea pig, and beef heart are used by different workers 

 and are of practically equal value. Heart muscle is finely chopped 

 and extracted at 37 C. in 10 volumes of absolute alcohol, for 

 from three to seven days. The jars in which the heart muscle is 

 kept should be shaken one or more times a day. If guinea pig 

 hearts are used, a jar of 100 c.c. of absolute alcohol is set aside, 

 and the hearts are ground up and dropped into the alcohol when- 

 ever a guinea pig has to be killed for any laboratory purpose. It 

 is important to remove all blood from the heart. If beef or human 

 heart is used it is important to remove all fat and tendon before 

 the heart is extracted. At the end of the period of extraction the 

 alcohol is filtered and the filtrate tested as described below. 



B 



CHOLESTERIN REENFORCED HEART EXTRACT 



The guinea pig hearts 1 are weighed before being added to the 

 alcohol. Thirty grams of finely ground heart are extracted at 

 least 14 days at 37 C. with 300 c.c. of absolute alcohol. This 

 is then filtered and half the filtrate is placed in a flask with an 

 excess (say 5 grams) of chemically pure cholesterin. This is kept 

 at 37 C. overnight and then in a water bath at 16 C. for three 

 hours (to precipitate excess of cholesterin). This saturated solu- 

 tion is then filtered and the other half of the original heart extract 

 is added to it, giving a heart extract which is half saturated with 

 cholesterin. 



C 



NOGUCHl's ACETONE-INSOLUBLE FRACTION OF HEART EXTRACT 



Whereas in the preceding antigen cholesterin was added to 

 the heart extract, Noguchi obtains a highly specific antigen by 

 removing the cholesterin and certain other substances from the 

 heart extract by means of precipitation with acetone (in which 



1 Some workers use human or beef hearts. 



