I. Problem Statement:
Successfully extracting the DNA from strawberries.
II. Background info:
DNA is the genetic information in organisms that codes for proteins, and controls the cells function. The DNA is a double helix molecule that is formed by various nucleotides which include Adenine, Thymine, Guanine, and Cytosine with sugar phosphate. Different organisms can have larger or smaller genes. DNA is also what makes up chromosomes during cell replication. Strawberries have a large amount of genes. The extraction solution which includes soap and salt is used to disrupt the cell’s plasma membrane and nuclear envelope, to make the DNA clump together. The salt breaks up the protein chains that bind the nucleic acids. DNA does not dissolve in ethanol, and the colder the ethanol is, the less DNA that will be broken down allowing us to view the DNA in the test tube.
If you add certain chemicals to the smashed up strawberry the sticky DNA can be retrieved from within the cells because of ethanol put into the mixture. IV. Experiment:
i. Independent- strawberry
ii. Dependent- The DNA
iii. Controlled- Extraction solution and ice cold ethanol B. Materials:
* Test tubes and test tube rack
* Extraction solution
* Ice cold ethanol
* Filter paper
* Ziploc baggies
* Eye dropper
1) Smash strawberries in a Ziploc bag until turned into paste 2) Add 10mL of extraction solution
3) Massage solution and strawberry mix for an additional amount of time (remembering to get as few bubbles as possible from massaging) 4) Filter though filter paper and dampen thoroughly
5) Pour 2-3 mL of mixture into test tube with eye dropper 6) Layer twice this volume with ice cold ethanol
7) Now wait a couple of minutes and you will be able to see thread like material separating from the strawberry mixture...