Prepare trypticase soy broth (M154) and dispense 15 ml portions into 20 × 150 mm tubes. Autoclave 15 min at 121°C.
Polymyxin B solution, 0.15%
Dissolve 500,000 units polymyxin B sulfate in 33.3 ml distilled water. Filter-sterilize and store in the dark at 4°C until needed. Before use, add 0.1 ml sterile 0.15% polymyxin B solution to 15 ml tryptic soy broth, and mix thoroughly.
Hypertext Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.