Description
Phenylalanine Agar is a biochemical differentiation medium for separating Proteus and Providencia from other Enterobacteriaceae.
Organisms that deaminate phenylalanine produce phenylpyruvic acid. After ferric-chloride reagent is added, a characteristic green colour develops in positive cultures.
A pure isolate is inoculated onto the slant and incubated at 36 ± 1°C for 18–24 hours. Ferric chloride and dilute hydrochloric acid are then added, and a green reaction is read within several minutes.
