2. 1.To provide students with an understanding that cells (and all living things) contain DNA 2. DNA is a physical structure that can be seen with an unaided eye

3. To prepare a solution containing their DNA. Precipitate their DNA to make it visible. Compare the DNA samples from others in the class to see that at this level, DNA looks the same no matter where it comes from.

4. DNA is found in the cells of all living things Students will be able to see their own DNA protein strands The solutions work together to release the DNA strands from the cell membranes Alcohol is added to the solution to precipitate the DNA

6. 1.One person-Obtain a beaker with detergent solution and larger beaker with alcohol. 2.Slowly pour the detergent coat the bottom of the tube. 2.Slowly pour the detergent in you test tube just to coat the bottom of the tube.

7. Obtain a cup of salt water. 2. Obtain a cup of salt water. Salt water Swish the salt water in your mouth for no less than 30 seconds, 3. Swish the salt water in your mouth for no less than 30 seconds, then return your “cheek water” to your cup. Remember to rub or chew on the inside surface of your cheeks to help dislodge more cells!

8. . Slowly pour enough “cheek water” to make the test tube half full. 4. Slowly pour enough “cheek water” to make the test tube half full. 5. Put the stopper on the test tube. Saliva +salt water

9. 6. Gently rock (NOT SHAKE!) the test tube back and forth to mix the contents, so that bubbles do not form. 7. Let it sit for ten minutes.

10. No Bubbles? Great! Remove the cap and keep the test tube upright from this point on! Ellen

11. . Tilt test tube slightly. Gently pour alcohol along the side of the tube until almost full. 8. Tilt test tube slightly. Gently pour alcohol along the side of the tube until almost full.

12. Observe for the precipitation of the DNA. Small bubbles with white strings attached will slowly make their way to the top of the alcohol. This is DNA! 9. Observe for the precipitation of the DNA. Small bubbles with white strings attached will slowly make their way to the top of the alcohol. This is DNA! 10. Let sit for 5 minutes. Use stirring rod later to pull it out.

13. 10. Wash cups and test tubes out with soap. 11. Return cups up front.

14. Did everyone’s DNA look the same? Why did some people have more DNA? What would have happened if you had been chewing gum?

15. Questions 1. Are you looking at a single strand of DNA? Yes or no, explain your1. Are you looking at a single strand of DNA? Yes or no, explain your answer.answer. 2. What was the purpose of the alcohol?2. What was the purpose of the alcohol? 3. What can be the benefits of extracting human DNA? Give at least3. What can be the benefits of extracting human DNA? Give at least two.two. 4. If you did not get a good result in this lab, what do you think you did wrong? (If you were successful, do you think there was anything you could have done to improve your results?)4. If you did not get a good result in this lab, what do you think you did wrong? (If you were successful, do you think there was anything you could have done to improve your results?) 5. Write a paragraph either agreeing with or arguing against the5. Write a paragraph either agreeing with or arguing against the necessity of genetic engineering in plants or animals. (Hint: Supportnecessity of genetic engineering in plants or animals. (Hint: Support your point of view)your point of view)

16. Experiment w/different concentrations of Gatorade/detergent Try different swishing methods Try using warm water to bathe the test tube until it is 55°C What other organisms can you extract DNA from?