|Yeast extract||20 g|
|Sodium thioglycollate||1 g|
|Distilled water||1 liter|
Dissolve solid ingredients of base and dispense 15 ml in 20 × 150 mm tubes or 100 ml in 170 ml prescription bottles. Autoclave tubes 10 min at 121°C and bottles 15 min at 121°C. Final pH, 7.0 ± 0.2. Refrigerate at 5°C. Add trypsin immediately before use.
|trypsin (1:250)||1.5 g|
|Distilled water||100 ml|
Stir trypsin in water to suspend. Let particles settle and filter-sterilize supernatant through 0.45 µm membrane.
Before use, steam or boil base for 10 min to expel dissolved oxygen. Add 1 ml trypsin to each 15 ml of broth or 6.7 ml trypsin to 100 ml of broth.
Hypertext Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.