Isolation of DNA from Onion

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This laboratory exercise is designed to show learners how DNA can easily be extracted from onion cells. It includes an optional test for the presence of DNA. Use this experiment to supplement any unit on DNA and genetics as well as to demonstrate how scientists study DNA. Adult supervision is recommended.

Quick Guide

Preparation Time:
4 to 24 hours

Learning Time:
45 to 60 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 11 - 18

Resource Types:
Activity, Experiment/Lab Activity


Materials List (per group of students)

  • 2 cm pieces of fresh onion
  • 100 ml beaker
  • 2 test tubes
  • Glass rod scored on one end
  • ICE COLD 95% ethanol
  • Palmolive liquid detergent
  • Non-iodized salt (sodium chloride)
  • Fresh meat tenderizer or fresh pineapple or papaya juice
  • Phenol red indicator


  • Life Sciences
    • Cells
    • Diversity of Life
      • Plants
    • Heredity and Genetics
      • DNA Structure and Function
  • Physical Sciences
    • Chemistry
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations

Informal Categories

  • Food and Cooking


To use this activity, learners need to:

  • see
  • see color
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Averill, Ellen