DNA Extraction from Kiwifruit, Study notes of Genetics

Download DNA Extraction from Kiwifruit and more Study notes Genetics in PDF only on Docsity! DNA Extraction from Kiwifruit Student Instructions Introduction DNA is present in the cells of all living organisms. This procedure is designed to extract DNA from kiwi in sufficient quantity to be seen and spooled. . Because DNA exists inside of cell and ultimately inside of the nucleus proteins must be denatured to locate the DNA. There are different proteins that form the membranes of the organelles and that allow DNA to coil so that it can fit inside of the nucleus. This activity is ideal for students to work in pairs, but each student will have a tube of DNA at the end. Some questions to get you thinking about today's lab: 1. One way to purify a molecule is to get rid of everything but that molecule. If we want to isolate DNA from kiwifruit, what do we have to get rid of? 2. What materials would you use to do that? 3. What can we do with the DNA once we've purified it? Materials • ziplock bags • jar or beaker that fits strainer or funnel strainer or funnel • cheese cloth (cut to cover the funnel) • ice water bath (a large mixing bowl works well) • extraction solution • kiwifruit • cold 95% ethanol or isopropanol • small test tubes (1 per student) Protocol 1. Get 6 pieces of kiwi and put them in a ziplock bag. 2. Add 20 ml of extraction solution to the ziplock bag. Make sure the bag is closed without much extra air. Mush the kiwi thoroughly but carefully so the bag doesnÕt break, for about 5 minutes. What does mushing the kiwi do? 3. What do you think the extraction solution is? What does it do to the kiwi? 4. Cool the kiwi mixture in the ice bath for a minute. Then mush the kiwi more. Cool, then mush. Repeat this several times. Why do we cool the mixture? 5. Filter the mixture through the cheesecloth. All the groups can combine their mixtures at this point, to filter together. What is being filtered out? What is going through the filter? 6. Dispense approximately 2 ml of kiwi solution into each test tube, one for each student. 7. Being careful not to shake the tubes, add approximately 2 ml of cold 95% ethanol to each tube. What do you think the ethanol does? Why do we want it cold? 8. Take a look at your tube. What do you see in the top portion of the liquid? Teacher's Version Teacher Guide: What is DNA? DNA Extraction from Kiwifruit Introduction DNA is present in the cells of all living organisms. This procedure is designed to extract DNA from kiwi in sufficient quantity to be seen and spooled. Because DNA exists inside of cell and ultimately inside of the nucleus proteins must be denatured to locate the DNA. There are different proteins that form the membranes of the organelles and that allow DNA to coil so that it can fit inside of the nucleus. This activity is ideal for students to work in pairs, but each student will have a tube of DNA at the end. Management & Grouping Procedures 1. Students will work in predetermined groups of 3. 2. Students will be assigned specific jobs within the group Example: time keeper and organizer Collect materials and clean up *All students will be responsible for making and recording observations Safety Students will be reminded of the following safety rules 1. Do no perform any experiment unless you are given permission by your teacher. 2. Do not touch, taste, or smell any of the lab materials. 3. No eating or drinking in the lab. Phase of Inquiry: Explore and Explain Some questions to get you thinking about the lab: One way to purify a molecule is to get rid of everything but that molecule. If we want to isolate DNA from kiwifruit, what do we have to get rid of? All parts of the cell besides the DNA, i.e. cell wall (kiwi is a plant, after all), cell membrane, mitochondria, Golgi apparatus, endoplasmic reticulum, vacuoles, lysosomes, nuclear membrane, etc. What materials would you use to do that? Something to mush the cells (blender or your hands), something to destroy membranes (soap dissolves them), something to get rid of proteins and carbohydrates (salt causes them to precipitate), something to separate insoluble cell stuff from soluble DNA, and something to help get the DNA (alcohol precipitates it).