Mannitol Salt Agar Medium | Selective Agar for Staphylococci

Product Name: Mannitol Salt Agar Medium
Specification: 250 g / bottle
Storage Condition: 5–30°C, dry and sealed
Shelf Life: 3 years

Product Overview:
Mannitol Salt Agar Medium is a selective and differential solid culture medium designed for the isolation and enumeration of staphylococci from clinical and nonclinical samples. The high sodium chloride concentration supports the growth of salt-tolerant microorganisms while inhibiting many other bacteria, making this medium suitable for routine microbiological analysis in clinical, food, pharmaceutical, and environmental laboratories.

Composition (per liter):

• Pancreatic Digest of Casein — 5.0 g

• Peptic Digest of Animal Tissue — 5.0 g

• Beef Extract — 1.0 g

• D-Mannitol — 10.0 g

• Sodium Chloride — 75.0 g

• Phenol Red — 0.025 g

• Agar — 15.0 g

Final pH: 7.4 ± 0.2 (25℃)

Preparation Instructions:

1. Suspend 111.0 g of the medium in 1000 mL of distilled or deionized water.

2. Mix thoroughly and heat with frequent agitation.

3. Boil for 1 minute to ensure complete dissolution.

4. Dispense into appropriate containers.

5. Sterilize at 121℃ for 15 minutes.

6. Cool to 45–50℃ and pour into sterile Petri dishes as required.

Appearance:

• Dehydrated Medium: Free-flowing light red powder

• Prepared Medium: Red, transparent gel

Quality Control:

Cultural characteristics are observed after incubation at 36 ± 1℃ for 24–48 hours using appropriate control microorganisms.

Precautions:

• For laboratory use only.

• Do not use dehydrated medium beyond shelf life or if caking or abnormal color is observed.