PetriKey

Concept

Transformation

Uptake of free environmental DNA

trans-for-MAY-shun

geneticshgtcompetencerecombination

High-yield clue

Transformation is uptake of naked (free) DNA from the surroundings by a naturally competent cell.

Overview

Horizontal gene transfer in which a competent bacterium takes up naked DNA released into its environment and incorporates it into its genome. Griffith's pneumococcus experiment is the classic teaching example.

Classification

  • Horizontal gene transfer
  • Uptake of naked DNA
  • Requires competence
  • Homologous recombination

Lab & identification clues

  • Natural-competence vocabulary
  • Griffith transforming-principle concept
  • Naked extracellular DNA source

Associations

  • Capsule-gene transfer in pneumococcus teaching
  • No vector or contact required
  • Basis of molecular-cloning transformation

Commonly confused with

  • Transduction
  • Conjugation

Your notes

Original microbiology concept summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC/WHO topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment selection, infection-control instructions, or specimen-handling guidance.

OpenStax: Microbiology 2e concept foundationssourceNCBI Bookshelf: Medical Microbiology general conceptssourceCDC: CDC public-health concept pagessource