A 53-foot trailer with 20 lab stations, microscopes, and all the necessary tools for seventh graders in Fred Yerzy’s and Linda Metcalf’s science classes to do a DNA extraction showed up recently on the Oakdale Junior High School campus.
That’s right, DNA extraction.
The Ag in Motion mobile lab, a mobile science classroom offered by the National Ag Science Center, made its first visit to OJHS due to the efforts of Principal John Simons. Seventh grade science students had been studying cell biology and what’s in the nucleus of cells – DNA – in their classes. The timing was perfect for the mobile lab to show up, Yerzy said. In the lab, the students went through a step-by-step process to extract DNA from strawberries.
“After 30 years of teaching this genetic material to students, I finally get to see first-hand DNA being extracted from a strawberry,” Yerzy said, adding that it was a “cool science day.”
He reported that a California seventh grade life science standard is for students to learn that “DNA is the genetic material of living things” and he wanted his students to learn in the cell biology unit that DNA really existed and that DNA is located in most eukaryotic cells in the nucleus, where chromosomes are located, which are made up of DNA and proteins.
Yerzy said that the Ag in Motion lab made this standard on DNA come to life for both his and Metcalf’s science classes.
“Students were able to see up close strands of DNA from a strawberry cell,” he said. “They first mashed a strawberry, added some soap, filtered the mix and added a drop of ethanol to help separate the DNA from the mix, and like magic the DNA appeared on a stick. Pretty amazing.”
He noted that the strands of DNA clung together on the probe stick the students used and that the material was very slimy. After collecting it on the stick, the students put it under the microscope and were able to see the DNA strands. Yerzy described it as looking sort of like transparent fiber optic tubes, cylinder-shaped strands. He said that they couldn’t see the helix or the rungs that make up the helix because a more powerful microscope is required for that but the lab exercise was very useful.
“It has really helped my lessons. Now every time I refer to DNA, it’s not abstract. They actually saw it... normally you can’t see it,” Yerzy said.
The students recorded their experiment findings in small laboratory research notebooks where they described the procedure, offered a hypothesis about what the DNA would look like, and drew a picture of their extraction set-up. They also described what the DNA actually did look like, and drew and labeled where it formed in their test tube. Through each of the four steps of the process, they described what the effect was on the strawberry cells. Then they summarized about why scientists would want to study the DNA of strawberries, if the DNA was pure or if there might be something attached to it, and answered other questions.
Yerzy said that he learned something in the mobile lab that day as well and said he would be able to duplicate the experiment in the classroom. It’s something he’d definitely like to add to his cell biology unit each year. However, he said that the mobile lab has the feel of a real research lab – it’s all white, with nice counters, and it’s easy to manage. He said it’s a very different atmosphere than in the classroom and he hopes to have the mobile lab return. He also said all the students were very attentive, engaged and receptive through the whole process.
The Ag in Motion mobile lab was provided free of charge and visits middle schools throughout the Central Valley. For more information go to www.agsciencecenter.org.