PetriKey

Lab method

Catalase test

Staph vs strep study branch

KAT-uh-lays

labenzymestaphstrepbubbles

High-yield clue

Catalase positive points toward staphylococci; catalase negative points toward streptococci in basic algorithms.

Overview

A biochemical test concept that detects catalase activity and is commonly taught to separate staphylococci from streptococci.

Classification

  • Biochemical test
  • Enzyme activity

Lab & identification clues

  • Bubble formation vocabulary
  • Hydrogen peroxide substrate concept

Associations

  • Staphylococcus
  • Streptococcus
  • Gram-positive cocci flowchart

Commonly confused with

  • Coagulase test
  • Oxidase 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.

OpenStax: Microbiology 2e staining, media, and biochemical-test foundationssourceNCBI Bookshelf: Medical Microbiology diagnostic concept foundationssource