What does the campy gas mixture primarily consist of?

The campy gas mixture is specifically designed to create an appropriate environment for the growth of microaerophilic bacteria, such as Campylobacter species. This mixture typically contains a blend of gases that provide an optimal atmosphere for these organisms, which require reduced oxygen levels for their metabolism.

The correct answer indicates that the campy gas mixture consists of a 10% concentration of carbon dioxide, 5% oxygen, and 85% nitrogen. The presence of carbon dioxide helps to mimic the natural conditions in the intestines where these bacteria usually reside, while the low level of oxygen creates a microaerophilic environment that is conducive to their growth. The high percentage of nitrogen acts as an inert filler gas that maintains the concentration of the other gases in the mixture, ensuring that the environment remains rich in carbon dioxide and low in oxygen.

Thus, the correct option captures the essential components of the campy gas mixture, illustrating its formulation aimed at fostering the growth of specialized bacteria that would otherwise thrive poorly in ordinary atmospheric conditions.