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  5. BAM Media M98: Modified Cellobiose-Polymyxin B-Colistin (mCPC) Agar
  1. Laboratory Methods (Food)

BAM Media M98: Modified Cellobiose-Polymyxin B-Colistin (mCPC) Agar

Media Index for BAM

January 2001

 Solution 1

Peptone 10 g
Beef extract 5 g
NaCl 20 g
1000× Dye stock solution* 1 ml
Agar 15 g
Distilled water 900 ml

Adjust to pH 7.6. Boil to dissolve agar. Cool to 48-55°C.

*1000× Dye stock solution

Bromthymol blue 4.0 g
Cresol red 4.0 g
Ethanol, 95% 100 ml

For consistent medium color, use dye solution rather than repeatedly weighing out dry dyes. Dissolve dyes in ethanol for 4% (w/v) stock solution. Using 1 ml of this solution per liter of mCPC agar gives 40 mg bromthymol blue and 40 mg cresol red per liter.

Solution 2

Cellobiose 10 g
Colistin 400,000 units
Polymyxin B 100,000 units
Distilled water 100 ml

Dissolve cellobiose in distilled water by heating gently. Cool. Add antibiotics.
Add Solution 2 to cooled Solution 1, mix, and dispense into petri dishes. Final color, dark green to green-brown.

NOTE: This medium, like TCBS, is very inhibitory and does not require autoclaving. Medium may be stored 2 weeks at refrigeration temperatures.

Storage: limit: 2 wks Temperature: 4°C

Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.

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