Lab method
Hippurate hydrolysis test
Purple color = GBS, C. jejuni, Listeria, Gardnerella
HIP-yoor-ate
High-yield clue
A positive (purple) hippurate result separates Group B strep from other beta-hemolytic strep and Campylobacter jejuni from C. coli.
Overview
A biochemical concept detecting hippuricase, which splits hippurate into glycine and benzoic acid; glycine then reacts with ninhydrin to give a purple color.
Classification
- Enzyme-detection concept
- Ninhydrin color readout
- Applied to strep and Campylobacter
Lab & identification clues
- Purple with ninhydrin = hippuricase positive
- Positive: S. agalactiae, C. jejuni, Listeria, Gardnerella
- Separates C. jejuni (+) from C. coli (-)
- Complements CAMP for Group B strep
Associations
- Group B strep confirmation vocabulary
- Campylobacter speciation study clue
- Beta-hemolytic and enteric differentiation
Commonly confused with
- CAMP test
- PYR test
Your notes
Original concept summary for coursework. Sources checked: OpenStax Microbiology 2e and NCBI Bookshelf Medical Microbiology; reviewed 2026-06. Describes vocabulary and interpretation concepts only; not a lab protocol and not for handling specimens or identifying patient isolates.