Details - Public Health Image Library(PHIL)

ID#:

15371

Caption:

This image depicts two test tubes, each having been filled with O/F glucose medium, and inoculated with an unknown oxidative bacterial organism. O/F glucose medium consists of agar, glucose, peptone and a pH indicator. Mineral oil had been added to the tube on the right in order to prevent air from interacting with the medium underneath. The organism could be identified as oxidative, or one that oxidizes glucose. Note that in the tube at right, sealed by its covering of mineral oil, there was no color change. This indicated that no metabolic reactions had taken place, for no oxygen was available. However, in left test tube, its contents were allowed to come into contact with environmental oxygen, and oxidation of the glucose contained in the O/F glucose medium did occur, which caused the pH in the upper reaches of the medium to become acidic, thereby, causing the indicator in the medium to turn a yellow color.

High Resolution:

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Content Provider(s):

CDC/ R. E. Weaver, MD, PhD

Creation Date:

1971

Photo Credit:

Links:

Categories:

CDC Organization