DNA barcoding

  • Audience
    Secondary school, Tertiary
  • Learning stage
    Stage 6
  • Learning area
    Science
  • Type
    Learning resources

On this page...

DNA barcoding is a genetic technique that scientists at the Australian Museum use to identify species and measure biodiversity. Use this series of video modules to learn more about laboratory 'tools of the trade', good scientific practice, and technologies such as the polymerase chain reaction (PCR), gel electrophoresis and DNA sequencing.

Then put your skills and knowledge to the test with our DNA barcoding activity! You can use real DNA sequences from scientists in the Australian Museum Research Institute (AMRI) and bioinformatic tools in 'DNA Subway' to solve a scientific puzzle.

The modules and activity can be completed over a series of lessons or set as part of a longer unit.

The Australian Museum would like to thank Sydney Grammar School for funding this project and acknowledge their commitment to supporting the development of science education resources for NSW schools.

3D animations by Dr Andrew Lilja and A/Prof John McGhee, 3D Visualisation Aesthetics Lab, UNSW Sydney.

DNA barcoding modules

  • What is DNA barcoding?

    Guiding questions

    What are the eight levels of taxonomy?

    Think of your favourite animal. Write down the name of its taxonomic group at each level of classification (for example, domain = eukarya, kingdom = animalia etc.). What features does it have with other organisms in each of these groups?

    What gene do scientists look at when they do DNA barcoding in animals? Can you think of two ways DNA barcoding can be used to answer a biological question?

  • Sample collection and labelling.

    Guiding questions

    Can you think of three ways to record your methods and results in an experiment? Why do you think it is important to keep accurate records in a scientific study?

    Give one example of a standard method to collect samples on a field trip. Why do you think it is important to collect data in a standardised way?

  • How to pipette

    Guiding questions

    You are to measure 0.4 mL of a solution with a pipette. How many microlitres is this?

    What are three ways you might contaminate a DNA sample in the laboratory? Describe how good laboratory practice could reduce the chance of this happening to you.

  • DNA extraction

    Guiding questions

    What is the name of the DNA structures inside the nucleus of a cell? Which organelle in animal cells also contains DNA? What is the main function of this organelle?

    What forms the outer border of an animal cell? Research a little further to describe how this is different to a plant cell.

    Name three of the unlabelled structures in the cell diagram in the video. What is the function of each of them?

    List the three main stages in a DNA extraction.

  • Ploymerase chain reaction (PCR)

    Guiding questions

    A PCR make many copies of a specific piece of DNA. Is this an exponential, bimodal or linear process?

    Name the three main stages in a PCR and describe in one sentence what happens in each stage.

    List the different reagents in a PCR. Explain how they ‘work together’ to produce a PCR product.

  • Agarose gel electrophoresis

    Guiding questions

    Are the following statements about agarose gel electrophoresis true or false?

    – It separates pieces of DNA based on their shape.
    – Long pieces of DNA migrate through an agarose gel faster than short pieces.
    – DNA has a negative charge and moves towards the positively charged terminal.
    – A dye in the agarose gel binds to DNA as it moves through the gel. This is illuminated by blue or ultraviolet light.

  • DNA sequencing

    Guiding questions

    What are the important differences between a PCR and a DNA sequencing reaction?

    What are the sequence of events that occur in this reaction?

    How does a sequencing machine produce a DNA sequence trace?

  • Databases and analysis

DNA barcoding activity

  1. Read the information about the case you need to solve under the Background drop-down heading.
  2. Click on the DNA sequence traces drop-down heading.
  3. Download the DNA sequence file for each of the five specimens and save them in a new folder on you computer. Each specimen has two sequences - a forward and reverse. Forward is the sequence of one strand of the CO1 PCR product, while reverse is the sequence of the complementary strand.
  4. Re-watch the video in module 8 'Databases and analysis' to learn how to use DNA Subway to identify each species.
  5. After you've identified the names of each species, read Barcoding bollworms at the Australian Museum to help you determine which of the five specimens are destructive crop pest species.