|Purple broth base
|Distilled water||900 ml|
Add purple broth base to distilled water. Dispense 9 ml into 16 × 125 mm tubes containing Durham tubes. Autoclave at 121°C for 15 min. Prepare carbohydrates, except esculin, as sterile 5% solutions.
Filter-sterilize or autoclave, as appropriate. Add 1 ml carbohydrate solution to 9 ml broth base to yield 0.5% carbohydrate in broth.
Add esculin directly into base broth to make a 0.5% solution and autoclave 15 min at 115°C. At room temperature, a 5% solution of esculin is a gel that cannot be pipetted.
Hypertext Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.