328 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(14) Sterilize at 100° for 30 minutes on 2 

 successive days or 10 pounds for 

 15 pounds in the autoclave. 

 References : Stickel and Meyer (1918 p. 80), 

 Harvey (1921-22 p. 101). 



1138. Frieber's Digest Extract Solution 



Constituents: 



1. Water 1000.0 cc. 



2. Physiological salt solution.. 3000.0 cc. 



3. Fibrin 



4. Beef extract, Liebig's 5.0 g. 



5. NaCl 5.0 g. 



Preparation : 



(1) Prepare Frieber's Fibrin Digest 

 Solution by digesting fibrin with pep- 

 sin and HCl (see medium 1110). 



(2) Add 5.0 g. Liebig's beef extract, 

 5.0 g. NaCl and 7.0 cc. of normal soda 

 solution to 1000.0 cc. of (1). 



(3) Neutralize to litmus and boil. 



(4) Distribute in a flask having a closely 

 fitting glass stopper. 



(5) Cool to 40°C. 



(6) Add 0.2 g. Grubler's trypsin, 10.0 cc. 

 chloroform and 5.0 cc. toluol. 



(7) Shake thoroly and place in the incu- 

 bator for 24 hours. 



(8) Filter thru a damp filter. 



(9) Dilute 1 part (8) with 3 parts physio- 

 logical salt solution. 



(10) Distribute in 5.0 cc. lots. 

 Sterilization: Sterilize in the steamer for 



one hour. 

 Use: To detect indol production. 

 Reference: Frieber (1921 p. 427). 



1139. Davis and Ferry's Hydrolyzed Gliadin 

 Solution 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Gliadin 20.0 g 



3. Tryptophane 0.4 g 



4. Tyrosine 0-75 g 



5. Cystine 0-2 g 



6. NaCl 2.5 g 



7. K2HPO4 1-5 g 



8. MgS04 0.25 g 



9. Gelatin 20.0 g 



Preparation : 



(1) Hydrolyze gliadin with 25.0% HoSO. 

 for 24 hours on sand bath. Tem- 

 perature not given. 



(2) Add Ba(OH) 2 until alkaline. Filter 



(3) Exactly neutralize with 10.0% H2SO4 

 and test for absence of both Ba and 

 SO4 ions. 



(4) Concentrate to thick syrup in 

 vacuum. 



(5) Dilute to a final solids content of 

 2.0% with distilled water. 



(6) Treat gelatin in the same manner as 

 gliadin (1) thru (5) above. 



(7) Dissolve 3, 4, 5, 6, 7 and 8 in 500.0 cc. 

 of (6). 



(8) Mix equal parts (7) and (5). 



(9) Adjust to pH from 8.0 to 8.2. 



(10) Steam 15 minutes and check the 

 reaction. 



(11) Distribute as desired. 

 Sterilization: Heat at 115°C. for 20 minutes. 

 Use: Cultivation of Bad. diphtheriae for 



toxin production. 

 Reference: Davis and Ferry (1919 p. 232). 



1140. Robinson and Rettger's Hydrolyzed 

 Edestin Casein Solution 



Constituents : 



1. Water 1000.0 cc. 



2. Casein 30.0 g. 



3. Edestin 30.0 g. 



4. Lactalbumin 30.0 g. 



5. Dextrose 0.5 g. 



Preparation : 



(1) Boil 50.0 g. of casein with 10.0% HCl 

 under a reflex condenser until the 

 solution no longer responds to the 

 Biuret test. 



(2) Evaporate on the water bath until 

 nearly all the HCl is removed. 



(3) Neutralize the remaining acid with 

 NaOH. This solution is of dark 

 brown color and is known as "Ca- 

 sein C." 



(4) Treat edestin and lactalbumin in 

 exactly the same manner as casein as 

 in steps (1) thru (3). 



(5) Dissolve 3.0% (3), 3.0% edestin 

 product and 3.0% lactalbumin prod- 

 uct in water. 



(Q') Adjust the reaction to neutral to 



litmus. 

 (7) Distribute in 20.0 cc. lots in 150.0 cc. 

 Erlenmeyer flasks. 

 Sterilization: Sterilize at 12 to 14 pounds 



pressure for 15 minutes. 

 Use: Cultivation of B. diphtheriae and 

 study toxin production. Authors re- 



