Description
Mannitol Salt Agar is a selective differential medium for isolating and presumptively identifying Staphylococcus aureus.
The high sodium-chloride concentration inhibits many competing organisms. Mannitol fermentation produces acid and changes phenol red to yellow, while non-fermenting staphylococci remain red or colourless.
Samples are streaked onto the agar and incubated at 35 ± 2°C for 18–72 hours. Yellow colonies with surrounding yellow medium are selected for confirmation.
