Selective medium for isolation and enumeration of Staphylococci. Recommended by USP for microbial limit tests. S. aureus strains produce colonies surrounded by yellow zones due to the fermentation of mannitol. Acid production is indicated by the phenol red dye. Non-pathogenic Staphylococci produce colonies surrounded by red or purple zones and are smaller in size. Most common organisms (Gram negatives) are inhibited by the high salt content.||Appearance:|Pale pinkish beige to beige free-flowing powder.||Solubility: Pale pinkish beige to beige free-flowing powder||Cultural Response: 24-48 hrs (35°C)|Microbiological Analysis:|E. coli. ATCC 8739: Inhibited|Proteus mirabilis ATCC 12453: Inhibited|Staphylococcus aureus, ATCC 6538 and ATCC 25923: Growth, yellow colony|Staphylococcus epidermidis, ATCC 12228: Light growth, pink-red colony||Final pH (25°C): 7.4 ± 0.2||Formulation Shown as g/liter:|Sodium Chloride 75.0|Agar 15.0|D-Mannitol 10.0|Pancreatic Digest of Casein 5.0|Peptic Digest of Animal Tissue 5.0|Beef Extract 1.0|Phenol Red 0.025|Total: 111g/L||Directions per Liter:|Dissolve 111 grams per liter of ddH2O, heating to boiling with stirring until completely solubilized. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121ºC (15psi).||Storage and Stability:|Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.