MLT GlobeHome › Techniques › PYR test
PYR test
Microbiology
Principle
Pyrrolidonyl arylamidase splits L-pyrrolidonyl-β-naphthylamide; the product turns red with a cinnamaldehyde reagent.
Procedure
- Rub colonies onto a PYR disk or strip moistened with water; wait 2 minutes, then add the developer.
Results
- Positive (red within 1–2 minutes): Streptococcus pyogenes, Enterococcus
- Negative (no colour or yellow): other beta-hemolytic streptococci, S. bovis group
📱 Practise with a timer, track your score and earn certificates in the free MLT Globe app – Google Play or practise online.