Mrs. Shupe’s DNA Lab

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Mrs. Shupe’s DNA Lab

Lei Chan, Contributor

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If you’re on Mrs. Atkins’ team, then you have already participated in Mrs. Shupe’s DNA Extraction Lab. For those who haven’t experienced this lab before, it is pretty straight forward. Students who participate in this lab will be able to study and see their very own cheek cell DNA, simply by following a few simple steps. By reading on, you can find out how to do this lab from the comfort of your home!

There is something special about this lab for this year’s seventh-grade students on Mrs. Atkins’ team. This year’s students are the first to be able to test this lab out! Mrs. Shupe has put a lot of planning and effort into this, and we sure think it paid off! The main experiment of this lab is being able to see your very own cheek DNA without a microscope or heavy scientific tools. Now Mrs. Shupe didn’t just do this lab for fun and games. Mrs. Shupe wanted to teach all her students how to follow proper lab procedures, follow directions carefully, and she wanted to show her students what their cells and DNA look like. If you would like to do this experiment at home, the ingredients and directions are listed below! Remember to have parental supervision and take precautionary safety equipment, such as gloves and goggles. Other than that, have fun!

 

  • Small paper cups ( Have the smallest size! )
  • 1 bottle of colorless sports drink ( Ex: Lemon Ice Gatorade )
  • Liquid dish soap ( We recommend a transparent version )
  • 1 wooden skewer ( You can find these in the baking aisle )
  • Rubbing or Isopropyl Alcohol ( One that is closest to 100% is best )
  • Narrow container with a lid ( Ex: Test Tube or clean and dry spice jars)
  • Pineapple Juice

Before you start, you’ll need to do some preparation for this experiment, and it involves with the isopropyl alcohol.  Twenty- four hours before you start, put the alcohol in your freezer. It won’t solidify but will be very chilled. Following the next day, take a mouthful of a sports drink and vigorously swish it around your mouth. If you don’t have any, just use a strong saltwater solution. Keep this up for about two minutes. When you’re done, spit the drink and cheek cell solution into a small paper cup, then pour it into in a test tube or empty spice jar of your choice. Make sure it fills about ⅓ of the container. After that, add liquid dish soap until your container is about half full. This will release the cheek cells from the solution you just spat out. Put the lid on and mix the contents by shaking the container and flipping it upside down several times. But be sure to be gentle, you don’t want too many bubbles to form caused by the dish soap. When you finish mixing the solution, add a couple of drops of pineapple juice. Pineapple juice has acids and enzymes that help speed up the process of releasing the cheek cells to be more visible. Then repeat the gentle mixing process. This is now the time to take the chilled isopropyl alcohol out of your freezer. First, take the lid off of the container that holds the cheek solution and slowly tilt the container in one hand. Use the other free hand to very gently trickle a small amount of alcohol down the inside of the jar so that the alcohol forms a layer floating on top of the cell solution. Now when you add the alcohol causes the DNA of the cells to be even more visible, letting you be able to twirl the DNA around the wooden skewer.  When you finish, close the lid on the container and set it aside for about one minute. When the minute is up, look very carefully at where the alcohol makes a layer. The layer will be floating on top of the cheek cell solution. A white band of gooey material will be suspended between the two liquid layers. This is the time where you want to grab a wooden skewer and gently put it down into the container so that the tip touches the material. Carefully twirl the skewer in one direction only; if you’re lucky the material will wind around the skewer so that you can lift it out through the alcohol layer to look more closely. Now behold your cheek cell DNA!

Now some of you may be wondering, why did we have to use all these ingredients and do all these long steps? Mrs. Shupe anticipated the following questions, and hopefully, the answers will fulfill your curiosity.

 

 

  • Why did I use dish soap?

 

Cell membranes are made up of two layers consisting of fats. Sugars and salts. The fats are on the inside of the membrane where they can avoid touching the water that surrounds the cell. Detergent molecules have two ends. One end is attracted to fat while to other is attracted to water. The cheek cell membrane attracts the detergent molecules from the fats, sugars, and salts. So when you add the dish soap to the cheek cell solution, the dish soap moves the cell membrane from the DNA.

 

   2.)  Why did I use the pineapple juice?

Pineapple juice has special enzymes that help further break down the cell membrane and make the DNA more visible.

   

`   3.)  Why did I use alcohol?

The DNA was dissolved in the water in the sports drink. DNA does not dissolve in alcohol. When the cold alcohol was layered on top of the cheek cell solution the DNA was extracted from the solution.

4.) Why did I twirl the skewer?

 Remember that famous DNA model? The DNA molecule is a very long strand with a double-helix twist. Your visible DNA material is actually many thousands of these strands clumped together. Gently twirling the skewer allowed many of these strands to wind around your skewer like thread around a spool.

 

Would you consider doing this at home? If so, remember to reread all these steps as you proceed with this lab. Have a parent with you as you handle the ingredients and do these steps. Stay safe and have fun!

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Mrs. Shupe’s DNA Lab