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Case of the Broken Beaker

Explore the use of DNA profiling and gel electrophoresis

Case of the Broken Beaker is an activity developed by Learning Undefeated to help students explore the use of DNA profiling and gel electrophoresis. In this lab, students will use restriction enzymes and agarose gel electrophoresis to create a genetic profile.

DNA profiling is a technique frequently used for solving crimes and confirming if people are related to each other. It involves the testing of skin cells, hair roots, or a small amount of blood or saliva.

Restriction Enzymes are enzymes found in bacteria that cut DNA. The reason the DNA needs to be cut is so that you can sequence the small fragments via gel electrophoresis.

Gel Electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, and protein according to their size. In gel electrophoresis, molecules are pushed through an electrical field with small pores, and separated based on their length. A molecules distance traveled is inversely related to it’s size, meaning the smaller the molecule, the greater distance it will travel.

Below are pre laboratory engagement and post laboratory extension activity suggestions that teachers may use in their classrooms as they see fit. Students who participate in the companion laboratory activity onboard MdBioLab will learn how to create a DNA profile in order to solve the Case of the Broken Beaker.

Learning Objectives

  • Standards Alignments + Connections

  • Activity Components

  • Additional Resources

    For further knowledge of gel electrophoresis and DNA matching, visit: http://www.sumanasinc.com/webcontent/animations/content/paternitytesting.html

    For further knowledge of restriction enzymes, visit: http://highered.mheducation.com/sites/dl/free/0072421975/196644/restriction_endonucleases.html

    Dolan DNA Learning Center
    Explore animations and other information on restriction endonucleases. Additional information on genetic engineering is also included if you’re feeling saucy!

    New England Biolabs
    Restriction endonuclease overview from the suppliers themselves

    Gel Electrophoresis Tools
    Run a virtual gel electrophoresis. This site also has many resources


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