Gas packs containing
citric acid, sodium carbonate and sodium borohydride
were used to maintain and check the anaerobiosis,
where citric acid releases carbon dioxide and sodium
borohydride releases hydrogen when they come in
contact with oxygen. An indicator strip of methylene
blue, when introduced into the jar, changes in colour
from white to blue in the absence of anaerobiosis.
Staphylococcus epidermidis was incubated in tryptic
soy broth (TSB) for 24 h at 37°C and adjusted to yield
approximately 1.0×108 CFU/ml.