Strawberry DNA Extraction

Strawberry DNA Extraction
This lesson is the first of the “Getting Started” series which includes DNA extraction, micro-pipetting and gel electrophoresis. This series introduces students to concepts and lab fundamentals that may prepare them to perform more advanced PCR labs including DNA extraction from their own cheek cells, insects (Wolbachia PCR) or food materials (GMO PCR). DNA extraction is a fundamental procedure used in many types of experiments.
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    The simple instructions introduce students on how to read protocols including the practice of reading ahead and following the procedures accurately. Extracting enough DNA onto a rod or loop is a fun activity allowing students to “see” the DNA they isolate. In this activity, ripe strawberries are the source for DNA extraction. Strawberries, by nature are very easy to squish and break down as they contain cellulase and pectinase that break down cell walls. Depending on the amount of time you have, students may do this experiment twice. The first time, students should be able to harvest strawberry DNA precipitate by following the protocol. The 2nd time through, students can omit or alter the amount of substances used in their extraction buffer to see the effect on the quantity of DNA extracted or choose a different fruit.

Lesson Resources
Student Guide – Download and edit student worksheets to be completed during the Strawberry DNA Extraction Lab.
Lesson Slides – Articulates with the student guide above and accompanying lesson plans below.
Lesson Plan – Suggested times for pacing, sequence and activities for the lab.
Supplemental Resources – Includes background information and more.

Lab Resources
Student Lab Protocol – Students follow these instructions when doing the Strawberry DNA Extraction Lab.
Preparing the Classroom for the Lab – How to set up group stations for this lab experience.
Inventory Guide – Reagents and materials checklist for one classroom kit. Includes equipment and classroom needs for the lab.

  • Students understand that all living things contain DNA that we can extract from cells
  • Students observe, describe and record the macroscopic nature of their extracted DNA
  • Through experimentation, students demonstrate that soaps break open cell and nuclear membranes while exploring the nature of polar interactions and the role NaCl plays in interactions with charged DNA molecule
  • Learn how to read and follow a basic procedure or protocol

Disciplinary Core Ideas:
LS1.A – Structure and Function
“All cells contain genetic information in the form of DNA molecules”

PE: HS-LS1-1 (See appx for a complete list)

Familiarity with the following biology concepts may be helpful for students prior to using the lesson resources.

  • Observe plant cells under microscope and identify the cell wall, cell membrane, cytoplasm and nucleus
  • The nucleus is surrounded by the nuclear membrane (envelope), which contains DNA molecules
  • DNA molecules code for proteins which carry out most of the work of cells
  • Review role of organelles in eukaryotic organisms

Kitty MeiStrawberry DNA Extraction