PetriKey

Lab method

Blood agar hemolysis

Alpha, beta, and gamma hemolysis vocabulary

HEE-mol-ih-sis

labagarhemolysisstrepstaphalpha

High-yield clue

Beta means complete clearing; alpha means partial greenish change; gamma means no hemolysis in study tables.

Overview

A differential-media concept used to describe red-blood-cell clearing patterns around colonies in coursework comparisons.

Classification

  • Differential media concept
  • Hemolysis vocabulary

Lab & identification clues

  • Alpha/beta/gamma terms
  • Streptococcal grouping context
  • Pattern recognition without procedure steps

Associations

  • Streptococcus pyogenes
  • Streptococcus pneumoniae
  • Streptococcus agalactiae

Commonly confused with

  • MacConkey agar concept
  • Chocolate agar X/V factors

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