Middle School Science

This quarter the 7th/8th grade Standard and Honors science classes are working on Heredity and Genetics. So that the students will have a physical representation of something that is normally to small to see with the naked eye, we will be extracting DNA from strawberries.

 

The long, thick fibers of DNA store the information for the functioning of the chemistry of life. DNA is present in every cell of plants and animals. The DNA found in strawberry cells can be extracted using common, everyday materials. We will use an extraction buffer containing salt, to break up protein chains that bind around the nucleic acids, and dish soap to dissolve the lipid (fat) part of the strawberry cell wall and nuclear membrane. This extraction buffer will help provide us access to the DNA inside the cells. The DNA is not soluble in ethanol, so we will add ethanol to the resulting solution to cause the DNA to precipitate out so that we can observe it.