Exercise 4-4 Micro. Lab: Mannitol Salts Agar
Mannitol Salts Agar
A differential, selective media used for the differentiation and isolation of Staphylococcus aureus.
Mannitol Salts Agar is made up of what 3 things?
7.5% sodium chloride
pH indicator phenol red
Phenol red is ____ at pH 6.8, ____ at 7.4 to 8.4 and ___ at above 8.4
What does mannitol do?
provides the substrate for fermentation and makes the medium differential
What does sodium chloride do?
makes the medium selective because its concentration is high enough to dehydrate and kill most bacteria
Why do staph bacteria thrive in the mannitol salt agar?
because of their adaptation to salty habitats such as human skin