All living things come with a set of instructions stored in their DNA, short for deoxyribonucleic acid. Whether you are a human, rat, tomato, or bacteria, each cell will have DNA inside of it (with some very rare exceptions). DNA is the blueprint for everything that happens inside the cell of an organism, and each cell has an entire copy of the same set of instructions. The entire set of instructions is called the genome. Scientists study DNA for many reasons. They can figure out how the instructions stored in DNA help your body to function properly. They can use DNA to make new medicines. They can genetically modify foods to be resistant to insects. They can figure out the suspect of a crime. They can even use ancient DNA to reconstruct evolutionary histories! How do scientists get the DNA out of a cell so that they can study it? This is called a DNA extraction, and there are many DNA extraction kits available from biotechnology companies for scientists to use in the lab. During a DNA extraction, a detergent will cause the cell to pop open, or lyse, so that the DNA is released into the liquid solution. Salt can also be added to make the tiny strands of DNA clump together. Then the DNA can be precipitated, or come out of the solution, by adding alcohol. In this biochemistry science project you will make your own DNA extraction kit from household materials and use it to purify DNA from strawberries. Strawberries are octoploid, which means they have eight copies of the DNA in their genome in every cell!Why use strawberries to test your DNA extraction kit? Because strawberry cells each have eight copies of the genome in every cell! When an organism has eight copies, called an octoploid, it has a lot more DNA per cell than an organism that only has one copy. Using DNA from strawberries will help you have a successful DNA preparation so you can purify a lot of DNA.
How can you extract the DNA out of a strawberry?
What does each ingredient do? (detergent, salt, alcohol)
Do you think you will be able to see the DNA without using a microscope?
BibliographyThis science project is from the "Understanding Genetics: Human Health and the Genome" exhibit at The Tech Museum of Innovation in San Jose, CA: