Environment 9

DNA
Based on and adapted from the Genetic Science Learning Center’s “How to Extract DNA from Any Living Thing” (http://learn.genetics.utah.edu/units/activities/extraction/) and BioRad’s “Genes in a bottle” (http://www.bio-rad.com/cmc_upload/Literature/54133/4110034B.pdf), 1 by Jennifer Doherty and Dr. Ingrid Waldron, Department of Biology, University of Pennsylvania, © 2007

Today you will extract DNA from some of your cells and learn more about DNA. Why is DNA so important in biology? What is the function of DNA? Where is DNA found in our bodies? Draw a simple diagram of a cell, showing the cell membrane and the DNA in chromosomes surrounded by a nuclear membrane.

Extracting DNA from Your Cells
Cells from the lining of your mouth come loose easily, so you will be able to collect cells containing your DNA by swishing a liquid around in your mouth. The cells from the lining of your mouth also come off whenever you chew food. How do you think your body replaces the cells that come off the lining of your mouth when you eat? To extract DNA from your cells, you will need to separate the DNA from the other types of biological molecules in your cells. What are the other main types of large biological molecules in cells? You will be using the same basic steps that biologists use when they extract DNA (e.g. to clone DNA or to make a DNA fingerprint). You will follow these 3 easy steps to extract the DNA:

Detergent eNzymes (meat tenderizer) Alcohol
Getting Your Sample of Cells Obtain a cup with sports drink. You will need to get thousands of your cheek cells in the sports drink in order to extract enough DNA to see. Therefore you should swish the sports drink around in your mouth vigorously for at least one minute. Then spit the drink back into the cup. Step 1: Detergent Add a small amount of detergent to a test tube (about 0.25 mL). Put a glove on the hand you will use to hold your test tube, not the hand you will use to pour. Now carefully pour the drink...