U.S. flag An official website of the United States government

On Oct. 1, 2024, the FDA began implementing a reorganization impacting many parts of the agency. We are in the process of updating FDA.gov content to reflect these changes.

  1. Home
  2. Food
  3. Science & Research (Food)
  4. Laboratory Methods (Food)
  5. BAM Media M95: Mannitol-Egg Yolk-Polymyxin (MYP) Agar
  1. Laboratory Methods (Food)

BAM Media M95: Mannitol-Egg Yolk-Polymyxin (MYP) Agar

Media Index for BAM

January 2001

Base

Beef extract 1 g
Peptone 10 g
Mannitol 10 g
NaCl 10 g
Phenol red (1% solution in 95% ethanol) 2.5 ml
Agar 15 g
Distilled water 900 ml

Heat with agitation to dissolve agar. Adjust pH so that value after sterilization is 7.2 ± 0.2. Dispense 225 ml portions to 500 ml Erlenmeyer flasks. Autoclave 15 min at 121°C. Cool to 50°C. MYP agar is commercially available from Difco.

Polymyxin B solution, 0.1%

Dissolve 500,000 units polymyxin B sulfate in 50 ml distilled water. Filter-sterilize and store in the dark at 4°C until needed.

Egg yolk emulsion, 50%

(see M51). Also available from commercial suppliers.

Final medium

To 225 ml melted base add 2.5 ml polymyxin B solution and 12.5 ml egg yolk emulsion. Mix and dispense 18 ml portions to sterile 15 × 100 mm petri dishes. Dry plates at room temperature for 24 h before use.


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

Back to Top