DNA Extraction Lesson Plan GK-12 Fellow : Mark Newell

GK-12 Teacher: Randy Hansen

Date of Lesson: Spring 2011 Grade Level:

7 t h Grade

Content Area & Topic: Agriculture Animals Astronom y Cells Other:

8 t h Grade

Chemistr y Engineering Environment Genetics

Health Physics Plants

Lesson Overview: In this lab you will prepare a solution of banana treated with salt, distilled water, and shampoo (detergent). The salt allows the DNA to precipitate out of the cold alcohol solution. The detergent breaks down the cell membrane by dissolving the lipids (fatty molecules) and proteins of the cell and disrupting the bonds that hold the cell membrane together. The detergent then forms complexes with these lipids and proteins, allowing them to be filtered out of solution with a coffee filter while leaving the cells’ DNA in the filtrate. The procedure uses household equipment and store supplies for the DNA extraction resulting in enough DNA to be seen and spooled. Length of Lesson: We were able to do this lesson in a 45-minute class period. Iow a Core Statement: Understand and apply knowledge of how different organisms pass on traits (heredity) Content Objectives: • Identify DNA as the molecule that contains the instructions for traits. • Understand the process of DNA extraction.

D e ve l o p e d b y: S y m b i , I o w a S t a t e ’ s G K - 1 2 P r o g r a m wi t h t h e N a t i o n a l S c i e n c e F o u n d a t i o n Engineering Research Center for Biorenewable Chemicals (CBiRC) at Iowa State University W eb s i t e : w w w . g k 1 2 . i a s t a t e . e d u E m a i l : s y m b i @ i a s t a t e . e d u

Materials: 1. 2 – five ounce plastic cups 2. Blender 3. 1 – Plastic spoon for measuring and mixing 4. 1 – Coffee filter 5. 20 mL of distilled water 6. Clear colored shampoo, such as Suave Daily Clarifying Shampoo 7. 3 bananas 8. Table salt, either iodized or non-iodized 9. Plastic transfer pipette 10. Glass stirring rod 11. 20 mL 95% ethanol (grain alcohol or 91% isopropyl (rubbing) alcohol (keep on ice) 12. 10 ounce package of frozen strawberries, partially thawed 13. 12.3 ounce package of tofu (soft or firm) 14. 1 cup orange juice 15. 2 tablespoons honey 16. Container with ice for alcohol Lesson Procedures: 1. In a blender, mix a ratio of one banana per one cup (250 mL) of distilled water. Blend for 1520 seconds until the solution is a mixture. 2. In one of the 5 ounce cups, make a solution consisting of 1 teaspoon of shampoo and two pinches of table salt. Add 20 mL (4 teaspoons) of distilled water or until the cup is 1/3 full. Dissolve the salt and shampoo by stirring slowly with the plastic spoon to avoid foaming. 3. Add three heaping teaspoons of the banana mixture from step 1 to the solution you made in step 2. Mix the solution with the spoon for 2-10 minutes. (The detergent dissolves the lipids that hold the cell membranes together, which releases the DNA into the solution. The detergent causes lipids and proteins to precipitate out of the solution, leaving the DNA. The salt enables the DNA strands to come together.) 4. While one member of your group mixes the banana solution, another member will make a funnel out the coffee filter and place inside the second 5 ounce plastic cup. Fold the edge of the filter around the cup so that the filter does not touch the bottom of the cup. To make the funnel from the coffee filter: a. Fold the coffee filter in half. b. Fold the coffee filter in half again, so that it is in quarters. c. Open one of the slits that you have folded to create the funnel. 5. Filter the mixture by pouring in into the filter and letting the solution drain for several minutes until there is approximately 5 mL (covers the bottom of the cup) of filtrate in the bottom of the cup. 6. Obtain 20 mL of cold alcohol in a test tube. For best results, the alcohol should be as cold as possible. 7. Fill the plastic pipette with the banana filtrate and add it to the alcohol. (DNA is soluble in alcohol. When alcohol is added ot the filtrate, the components of the mixture, except for DNA, stay in solution while the DNA precipitates out into the alcohol layer.) 8. Let the solution sit for 2 to 3 minutes without disturbing it. It is important not to shake the test tube. You can watch the white DNA precipitate out into the alcohol layer. When good results are obtained, there with be enough DNA to spool on to a glass-stirring rod. The DNA has the appearance of white, stringy mucus. D e ve l o p e d b y: S y m b i , I o w a S t a t e ’ s G K - 1 2 P r o g r a m wi t h t h e N a t i o n a l S c i e n c e F o u n d a t i o n Engineering Research Center for Biorenewable Chemicals (CBiRC) at Iowa State University W eb s i t e : w w w . g k 1 2 . i a s t a t e . e d u E m a i l : s y m b i @ i a s t a t e . e d u

MAKING A SMOOTHIE 9. Add the following ingredients to a blender and blend until smooth. a. ¼ package of tofu (cut up into pieces) b. Package of frozen strawberries, partially thawed c. 1 ripe banana (cut up into pieces) d. 1 cup of orange juice (add more for a thinner consistency) e. 2 tablespoons of honey 10. Distribute the smoothie in 5 ounce cups. This recipe makes enough for 10 five-ounce cups. 11. Evaluate your DNA and smoothie. Evaluation/ Assessment: Students were evaluated on their ability to follow directions and their DNA extraction results. References: Adapted from an original procedure by the Office of Biotechnology, Iowa State University. Additional Uses and Comments: The students loved making smoothies and being able to have a treat at the end of class! Handouts and Deliverables to Students: See following pages for deliverables to students and to implement this lesson plan into your classroom.

D e ve l o p e d b y: S y m b i , I o w a S t a t e ’ s G K - 1 2 P r o g r a m wi t h t h e N a t i o n a l S c i e n c e F o u n d a t i o n Engineering Research Center for Biorenewable Chemicals (CBiRC) at Iowa State University W eb s i t e : w w w . g k 1 2 . i a s t a t e . e d u E m a i l : s y m b i @ i a s t a t e . e d u

IS THERE DNA IN MY FOOD??? DNA is present in the cells of all living organisms. This procedure uses household equipment and store supplies to extract DNA from a banana in sufficient quantity to be seen and spooled.

The process of extracting DNA from a cell is the first step for many laboratory procedures in biology. The scientist must be able to separate DNA from the unwanted substances of the cell gently enough so that the DNA does not denature (break up).

All laboratory DNA extractions include four major steps: 1) Collect the cells, 2) Release the DNA from the cells, 3) Separate the DNA from proteins and lipids in the cells, and 4) Isolate the DNA.

In this lab you will prepare a solution of banana treated with salt, distilled water, and shampoo (detergent). The salt allows the DNA to precipitate out of the cold alcohol solution. The detergent breaks down the cell membrane by dissolving the lipids (fatty molecules) and proteins of the cell and disrupting the bonds that hold the cell membrane together. The detergent then forms complexes with these lipids and proteins, allowing them to be filtered out of solution with a coffee filter while leaving the cells’ DNA in the filtrate.

Once you have successfully extracted the DNA, the remaining banana mixture is made into a delicious smoothie by adding another banana, orange juiece, frozen strawberries, tofu, and blending.

MATERIALS 1. 2 – five ounce plastic cups 2. Blender 3. 1 – Plastic spoon for measuring and mixing 4. 1 – Coffee filter 5. 20 mL of distilled water 6. Clear colored shampoo, such as Suave Daily Clarifying Shampoo 7. 3 bananas 8. Table salt, either iodized or non-iodized 9. Plastic transfer pipette 10. Glass stirring rod 11. 20 mL 95% ethanol (grain alcohol or 91% isopropyl (rubbing) alcohol (keep on ice) 12. 10 ounce package of frozen strawberries, partially thawed 13. 12.3 ounce package of tofu (soft or firm) 14. 1 cup orange juice 15. 2 tablespoons honey 16. Container with ice for alcohol D e ve l o p e d b y: S y m b i , I o w a S t a t e ’ s G K - 1 2 P r o g r a m wi t h t h e N a t i o n a l S c i e n c e F o u n d a t i o n Engineering Research Center for Biorenewable Chemicals (CBiRC) at Iowa State University W eb s i t e : w w w . g k 1 2 . i a s t a t e . e d u E m a i l : s y m b i @ i a s t a t e . e d u

PROCEDURE 1. In a blender, mix a ratio of one banana per one cup (250 mL) of distilled water. Blend for 15-20 seconds until the solution is a mixture. 2. In one of the 5 ounce cups, make a solution consisting of 1 teaspoon of shampoo and two pinches of table salt. Add 20 mL (4 teaspoons) of distilled water or until the cup is 1/3 full. Dissolve the salt and shampoo by stirring slowly with the plastic spoon to avoid foaming. 3. Add three heaping teaspoons of the banana mixture from step 1 to the solution you made in step 2. Mix the solution with the spoon for 2-10 minutes. (The detergent dissolves the lipids that hold the cell membranes together, which releases the DNA into the solution. The detergent causes lipids and proteins to precipitate out of the solution, leaving the DNA. The salt enables the DNA strands to come together.) 4. While one member of your group mixes the banana solution, another member will make a funnel out the coffee filter and place inside the second 5 ounce plastic cup. Fold the edge of the filter around the cup so that the filter does not touch the bottom of the cup. To make the funnel from the coffee filter: a. Fold the coffee filter in half. b. Fold the coffee filter in half again, so that it is in quarters. c. Open one of the slits that you have folded to create the funnel. 5. Filter the mixture by pouring in into the filter and letting the solution drain for several minutes until there is approximately 5 mL (covers the bottom of the cup) of filtrate in the bottom of the cup. 6. Obtain 20 mL of cold alcohol in a test tube. For best results, the alcohol should be as cold as possible. 7. Fill the plastic pipette with the banana filtrate and add it to the alcohol. (DNA is soluble in alcohol. When alcohol is added ot the filtrate, the components of the mixture, except for DNA, stay in solution while the DNA precipitates out into the alcohol layer.) 8. Let the solution sit for 2 to 3 minutes without disturbing it. It is important not to shake the test tube. You can watch the white DNA precipitate out into the alcohol layer. When good results are obtained, there with be enough DNA to spool on to a glass-stirring rod. The DNA has the appearance of white, stringy mucus. MAKING A SMOOTHIE 9. Add the following ingredients to a blender and blend until smooth. a. ¼ package of tofu (cut up into pieces) b. Package of frozen strawberries, partially thawed c. 1 ripe banana (cut up into pieces) d. 1 cup of orange juice (add more for a thinner consistency) e. 2 tablespoons of honey 10. Distribute the smoothie in 5 ounce cups. This recipe makes enough for 10 five-ounce cups. 11. Evaluate your DNA and smoothie.

D e ve l o p e d b y: S y m b i , I o w a S t a t e ’ s G K - 1 2 P r o g r a m wi t h t h e N a t i o n a l S c i e n c e F o u n d a t i o n Engineering Research Center for Biorenewable Chemicals (CBiRC) at Iowa State University W eb s i t e : w w w . g k 1 2 . i a s t a t e . e d u E m a i l : s y m b i @ i a s t a t e . e d u