CRITERION™ Mannitol Salt Agar (MSA) is a selective and differential culture medium designed for the isolation and differentiation of pathogenic Staphylococcus species, particularly Staphylococcus aureus, from clinical, food, and environmental samples.

MSA uses a high sodium chloride concentration (7.5%) to inhibit the growth of most other bacteria while allowing halotolerant Staphylococci to thrive. The presence of mannitol and phenol red enables differentiation: pathogenic S. aureus ferments mannitol, producing acid that changes the medium’s color from red to yellow, while non-pathogenic Staphylococcus epidermidis does not.

The CRITERION™ line by Hardy Diagnostics offers exceptional quality, consistency, and ease of use. The wide-mouth, easy-grip 500g bottle simplifies handling and reduces contamination risk, while the high-purity formulation ensures reproducible growth results across testing applications.

Features and Benefits:
• Selective for halotolerant bacteria, especially Staphylococcus spp.
• Differential color change to distinguish S. aureus (yellow colonies) from non-pathogenic species (red colonies)
• Ideal for use in clinical, food, and cosmetic microbiology
• Supplied as dehydrated powder for customizable batch preparation
• Wide-mouth bottle reduces dust and spillage during dispensing
• Fast-dissolving formula for convenient media preparation
• Available in multiple container sizes (500g, 2kg, 10kg, and 2L pre-measured Mylar® bags)
• Manufactured under ISO 13485 and cGMP quality systems for reliable performance