DNA is Everywhere!
In this lesson students learned all about deoxyribonucleic acid, more commonly known as DNA. After getting a brief overview of DNA’s role in the storage of genetic information, students followed a DNA extraction protocol experiment and successfully extracted DNA from strawberries by breaking down the cell membranes with water, detergent and salt. By breaking down the cell wall, membrane, and nuclear membrane, students were able to isolate the nucleic acids.
They then added some very cold isopropyl alcohol to the resulting lysate (the fluid and cell remnants left over when the cells were broken up), which caused the DNA to become visible at the border between the aqueous solution and the alcohol. The addition of alcohol to the cell lysate allows the nucleic acids become visible without a microscope! The activity involved a number of different steps and helped emphasize the importance of following directions carefully. The young scientists were rewarded for their diligence by seeing DNA in their test tubes at the end of the lab!