Pre-AP Biology class finds DNA in strawberries
October 1, 2021
Evan Webb’s Pre-AP Biology class conducted a strawberry lab on Sept. 17 to find the DNA of a strawberry.
Webb said, “This was a basic lab activity that was fun, and helped classes familiarize themselves with laboratory conduct and practice team collaboration.” The lab was good for students to get a hands-on learning experience when it comes to conducting experiments.
“Students should have been exposed to the idea that macromolecules are real and have functions in our organic world,” said Webb. In the lab students were supposed to get a visual and hands-on experience with the macromolecules they were studying in Webb’s class.
He explained the experiment and said, “First, the soap dissolved the cell membranes for the strawberries. This allowed the contents of the cells, including DNA, to escape their containers (cells).”
Once the students completed this step, they used salt to dissolve proteins.
“Second, the salt dissolved the proteins attached to the DNA and kept any more proteins from materializing. This isolated the DNA, and prevented its extraction from being complicated by other macromolecules,” Webb said.
Students then carefully poured rubbing alcohol down the side of the beaker creating an alcoholic layer above the strawberry solution. “The alcohol created a filter which allowed DNA (now clumping to itself in larger and larger forms) to rise up out of the strawberry and up to the top of the alcohol,” said Webb. Students then took coffee stirrers and paper clips to extract the clumps of strawberry DNA.
Nash, a student in Webb’s 3rd period class said that the strawberry lab was very engaging and got students thinking in Webb’s class. Nash said, “If you are a visual learner it makes it easier.”