Material:
- Plant tissue (strawberries orsplit peas)
- 400-mL beaker
- Blender
- Table salt
- Tablespoon
- 1/8 teaspoon
- Liquid detergent
- Test tubes and test tuberack
- Meat tenderizer
- Glass rods
- Ice-cold 70–95% ethanol
- Ice-cold dH2O
- Strainer
Procedure – DNA Extraction
1.Combine in a blender:
- 1/2 cup frozen green split peasor approx. 1/2 cup frozen strawberries
- 1/8 teaspoon table salt
- 1 cup cold (refrigerated or useice to chill) water
2.Cover and blend on the high setting for 30 seconds.
3. Pour the blended material through a strainerinto a 400-mL beaker. Discard the solid material trapped by thestrainer into the trash. This step removes the seed coat and thecell walls from the plant cells.
4. Add 2 tablespoons of liquid detergent to your beaker andswirl to mix. Let the mixture stand for approximately 10minutes.Detergents dissolve lipids, such as phospholipids in plasma andnuclear membranes.
5. Obtain a test tube for each member of each ofyour group.pour the mixture into the test tubes until they are eachabout 1/3 full.
6. Add a pinch of meat tenderizer to each test tube andstir gently with a glass rod. if you stir. vigorously, youwill break the DNA into short strands that are had to see. Meattenderizer contains enzymes that digest histones, the proteinsaround which the DNA is wound.
7. Tilt your test tube and slowly pour cold 70-95%ethanol down the side of the tube so it forms a layer on top of theDNA mixture until you have the same volume of alcohol as the DNAmixture.
8. After a few minutes, the DNA will rise into thealcohol layer. DNA forms a whitish layer at the interface betweenthe alcohol and the lower cell debris-containing layer.
1:Why did you add detergent to the homogenized tissuesample?
2:How did you remove the cell walls.
3:Why did you add meat tenderizer to your test tubes?.
4:What are histones
