🦠microbiology review

Differential media

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Differential media are specialized types of culture media designed to distinguish between different types of microorganisms based on their biological characteristics. They often contain indicators that reveal differences in microbial metabolism or enzymatic activity.

5 Must Know Facts For Your Next Test

  1. Differential media contain specific indicators, such as dyes or pH indicators, that change color in response to microbial metabolic activities.
  2. These media help identify and differentiate closely related bacterial species by producing distinct visual changes.
  3. MacConkey agar is a common type of differential medium used to differentiate lactose fermenters from non-fermenters among Gram-negative bacteria.
  4. Blood agar is another example where hemolysis patterns (alpha, beta, gamma) can be observed to differentiate bacterial species based on their ability to lyse red blood cells.
  5. The use of differential media is crucial in clinical diagnostics for rapidly identifying pathogenic microorganisms.

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