Oxacillin Resistance Screening Agar Base for MRSA Detection

Oxacillin Resistance Screening Agar Base is a dehydrated culture medium designed for the selective screening of methicillin-resistant Staphylococcus aureus (MRSA).
It is provided as a dry powder, packaged in 250g bottles, with a shelf life of 3 years at room temperature.

Composition per liter:

• Peptone: 11.8 g

• Yeast Extract: 9.0 g

• Mannitol: 10.0 g

• Sodium Chloride: 55.0 g

• Lithium Chloride: 5.0 g

• Aniline Blue: 0.2 g

• Agar: 12.5 g

• Final pH: 7.2 ± 0.2 (at 25°C)

Preparation:
Suspend 103.5 g of the powder in 1 L of distilled or deionized water. Heat to dissolve completely, dispense, and sterilize by autoclaving at 121°C for 15 minutes. Mix well after sterilization to prevent agar sedimentation. Cool to 55°C and aseptically add one vial of Polymyxin B (10,000 units) and one vial of Oxacillin (0.4 mg) per 200 ml medium before pouring plates.