So...What Just Happened?
Crushing the strawberries breaks open many of the strawberry cells, where the DNA is. The soap in the shampoo breaks down the membranes of the cells, releasing the DNA. The salt makes the DNA molecules stick together, and separate from the proteins that are also released from the cells. The strainer will retain cell debris and unmashed pieces of fruit. The DNA will pass through the gauze into the glass.
DNA is not soluble in alcohol, so it precipitates. What you see are long, ropelike DNA molecules in the alcohol.
What is DNA?
DNA is inside the cells of every living thing, including you. The information contained in your DNA is an important part of who you are because it includes characteristics such as eye color and blood type that you inherited from your parents. Long, twisting molecules of DNA inside cells wind tightly around proteins to form chromosomes.
Each chromosome contains segments of DNA called genes. Genes tell every cell in your body what to do. They are the builtin assembly, instruction, and repair manuals for every living thing.
Why do Scientists Extract DNA?
Extracted DNA is used in many ways:
- to locate a gene that causes an inherited characteristic, such as a hereditary disease
- to determine a child's biological parent
- to match suspects with evidence, such as bloodstains, from the scene of a crime
- to make a clone
- to replace genes in an organism with genes from another (gene replacement therapy)