MacConkey Agar with Polymyxin B and Gentamicin – Selective Medium for Burkholderia cepacia Detection in Cosmetics (250g)

MacConkey Agar with Polymyxin B and Gentamicin is a selective and differential culture medium designed for the isolation of Burkholderia cepacia from cosmetic products.

Based on classic MacConkey agar, this formulation contains lactose, bile salts, and neutral red for differentiating lactose-fermenting from non-fermenting organisms. The addition of Polymyxin B and Gentamicin provides strong selectivity by inhibiting background flora, enabling accurate detection of Burkholderia cepacia.

This medium is widely applied in:

• Cosmetic microbiology testing

• Quality control laboratories

• Pharmaceutical and personal care product safety evaluation

Composition (per liter):

• Peptone – 20.0 g

• Lactose – 10.0 g

• Sodium Chloride – 5.0 g

• Bile Salts – 5.0 g

• Neutral Red – 0.03 g

• Agar – 14.0 g

• Final pH: 7.2 ± 0.2 (at 25°C)

Preparation & Instructions:

1. Suspend 54.0 g of powder in 1 L distilled or deionized water.

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

3. Dispense into suitable containers.

4. Sterilize by autoclaving at 115°C for 20 minutes.

5. After sterilization, shake gently to prevent agar from settling at the bottom.

6. Cool to 50–55°C.

7. For every 200 ml of medium, aseptically add:

   • 2 vials Polymyxin B (25,000 units each)

   • 1 vial Gentamicin solution

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