LIQUID MEDIA 47 
Glucose Formate Broth (Kitasato). 
Nutrient broth............ Leen cence eee 1000 e.e. 
Glucose (CgeH1206).... 2... cee ee 20 gms. 
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Sodium formate (H—C—O—Na)............. 4 gms. 
Tube and sterilize. 
Peptone Solution (Dunham). 
Witte’s peptone... 2... .. 0. ccc cece eee 10 gms. 
Distilled water... 2.0.0.0... 0. cece eee 1000 e.c. 
Reaction not adjusted. 
Carbonated Broth (Besson, 1913). Add CaCQs, 2 per cent to lac- 
tose, mannite glucose, etc., broth before distributing into test tubes. 
CaCOQOsz is most frequently added to lactose broth. When an organ- 
ism which ferments lactose is grown in a CaCQO3 lactose broth, the acids 
formed act on the CaCQOs giving off COs. 
Serum Broth (Besson, 1913). This medium is made by adding 
to tubes of ordinary sterile broth one-half, one-third, or one-quarter 
their volume of blood serum or blood collected under aseptic conditions. 
It is best to incubate the tubes before using in order to be certain that 
they are sterile. 
Dextrose Potassium Phosphate Broth. 
Witte’s peptone... 02.0... eee eee eee eee ee 5 gms. 
Dextrose (CgH120¢).......... 0.00. eee 5 gms. 
Di-potassium hydrogen phosphate (KeHPO,). 5 gms. 
Heat with occasional stirring over steam for twenty minutes. 
Filter and cool to 20° C. Dilute to 1000 c.c. with distilled water. 
Tube and sterilize. (Standard Methods of Water Analysis, 1917, ° 
p. 210:) . 
Tryptophane Broth. To 1000 c.c. distilled water add 5 gms. di- 
potassium phosphate, 0.3 gm. tryptophane, and 1 gm. peptone. Heat 
until the ingredients are thoroughly dissolved, tube and sterilize at 
15 lbs. for fifteen minutes. Some American peptones are standardized 
to contain a certain amount of tryptophane. If such peptone is used 
the tryptophane in the above formula may be omitted and the peptone 
increased to 5 gms. 
