298 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(5) Allow to sediment at room tem- 

 perature. 



(6) Pipette off the clear supernatant 

 extract and test sterility. 



(7) Store in ice chest until ready for 

 use. Readjust the reaction of the 

 extract from pH = 7.3 to 7.5 just 

 before use. 



(8) Separate serum from sterile defib- 

 rinated blood by repeated centrifu- 

 gation. Serum is to be free from 

 blood pigment. 



(9) Dilute (8) in (2) in varying propor- 

 tions from 1:10 to 1:10,000. 



(10) Add yeast e.xtract (7) (amount not 

 given) to (9). 



Sterilization: Sterilization of bouillon not 

 given. Yeast infusion sterilized by boil- 

 ing in step (4). 



Use: To study bacterial nutrition of Bacil- 

 lus influenzae. Authors reported no 

 growth of B. influenzae without yeast 

 extract. No growth when serum diluted 

 1:10,000. 



Reference: Thjotta and Avery (1921 

 p. 109). 



974. Thjotta and Avery's YeastBlood 

 Bouillon 



Constituents : 



1. Distilled water 400.0 cc. 



2. Brewer's yeast 100.0 g. 



3. Bouillon 



4. Blood 

 Preparation : 



(1) Exact method of preparation of 

 bouillon not given. 



(2) Adjust the reaction of (1) to pH 

 = 7.8. 



(3) Emulsify 100.0 g. of brewer's yeast 

 in 400.0 cc. of distilled water with 

 the reaction of pH = 4.6. 



(4) Boil over a free flame for 10 minutes. 



(5) Allow to sediment at room tem- 

 perature. 



(6) Pipette off the clear supernatant 

 extract and test sterility. 



(7) Store in the ice chest until ready for 

 use. Readjust the reaction of the 

 extract from pH = 7.3 to 7.5 just 

 before use. 



(8) Boil whole blood 10 minutes. 



(9) Centrifuge repeatedly until all the 

 coagulated proteins have been 

 thrown down. 



(10) Dilute the supernatant fluid from 

 (9) in varying proportions from 1 : 10 

 to 1:10,000 with bouillon. 



(11) Add yeast extract (7) (amount 

 not given). 



Sterilization: Sterilization of bouillon not 

 given. Sterilization of yeast infusion 

 and blood is effected in steps (4) and (8) 

 in the preparation. 



Use: To study bacterial nutrition of Bacil- 

 lus influenzae. Author reported nearly 

 as good growth without the yeast extract 

 as with it added. No growth after blood 

 dilution of 1:1000. 



Reference: Thjotta and Avery (1921 

 p. 109). 



975. Thjotta and Avery's Yeast Blood Cell 

 Bouillon 



Constituents : 



1. Distilled water 420.0 cc. 



2. Brewer's yeast 100.0 g. 



3. Bouillon 



4. Red blood cells 

 Preparation : 



(1) Exact method of preparation of 

 bouillon not given. 



(2) Adjust the reaction of (1) to pH 

 = 7.8. 



(3) Emulsify 100.0 g. of brewer's yeast in 

 400.0 cc. distilled water with the 

 reaction of pH = 4.6. 



(4) Boil over a free flame for 10 minutes. 



(5) Allow to sediment at room tem- 

 perature. 



(6) Pipette off the clear supernatant 

 extract and test sterility. 



(7) Store in ice chest until ready for use. 

 Readjust reaction of the extract 

 from pH = 7.3 to 7.5 just before use. 



(8) Wash the red blood cells from 20.0 cc. 

 sterile defibrinated blood three 

 times, each time with 50.0 cc. sterile 

 salt solution. The cells are removed 

 by centrifugation. 



(9) Take up the cells in sterile distilled 

 water to the original volume of 

 blood. 



(10) Dilute (9) with (2) in varying pro- 

 portions from 1:10 to 1:100,000. 



(11) Add yeast extract (7) (amount not 

 given). 



Sterilization: Sterilization of bouillon not 

 given. Sterilization of yeast infusion 

 effected by boiling in step (4), 



