This is a test commonly used when trying to identify Gram-negative ... Because the same pH indicator (phenol red) is also used in these fermentation tubes, the same results are considered positive ...

Compounds with a phenol group will form a blue, violet, purple, green, or red-brown color upon addition of aqueous ferric chloride. This reaction can be used as a test for phenol groups. Mix several ...

This is a test commonly used when trying to identify Gram-negative ... Because the same pH indicator (phenol red) is also used in these fermentation tubes, the same results are considered positive ...