m-PA Agar Base (Pseudomonas aeruginosa Agar, m-PA Agar) – Selective Medium for Pseudomonas aeruginosa Detection in Water (250g)

m-PA Agar Base (also known as Pseudomonas aeruginosa Agar, m-PA Agar, or m-Pseudomonas aeruginosa Agar) is a selective culture medium used for the membrane filtration method to isolate and enumerate Pseudomonas aeruginosa from water samples.

The medium contains multiple carbohydrates (xylose, lactose, sucrose) for differentiation, while phenol red serves as a pH indicator. Sodium thiosulfate and ferric ammonium citrate are included for H₂S detection. For selectivity, additional supplements such as sodium sulfadiazine solution, m-PA agar supplement, nalidixic acid solution, and kanamycin solution must be added after sterilization.

This medium is widely applied in:

• Drinking water safety testing

• Environmental and industrial water monitoring

• Microbiological research laboratories

Composition (per liter):

• Agar – 15.0 g

• Sodium Thiosulfate – 6.8 g

• L-Lysine·HCl – 5.0 g

• Sodium Chloride – 5.0 g

• Xylose – 2.5 g

• Yeast Extract – 2.0 g

• Lactose – 1.25 g

• Sucrose – 1.25 g

• Ferric Ammonium Citrate – 0.8 g

• Phenol Red – 0.08 g

• Final pH: 7.1 ± 0.2 (at 25°C)

Preparation & Instructions:

1. Suspend 39.7 g of medium in 1 L distilled or deionized water.

2. Heat to boiling for at least 1 minute until completely dissolved.

3. Dispense into suitable containers.

4. Sterilize by autoclaving at 121°C for 15 minutes.

5. Shake gently after sterilization to prevent agar sedimentation.

6. Cool to 50–55°C, then aseptically add per 100 ml medium:

   • 1 vial sodium sulfadiazine solution

   • 1 vial m-PA agar supplement

   • 1 vial nalidixic acid solution

   • 1 vial kanamycin solution

7. Mix gently, pour into Petri dishes, allow to solidify, and store for use.