Students Test DNA in Lab

By Richard Oletsky ‘15 

The classroom did not look like any ordinary classroom. It had laboratory equipmment all around, and did not have desks like one would normally see. This is because this wasn’t a classroom, it was a lab.

Ms. Jessica Ross and her AP Biology class got the opportunity to visit the Dolan DNA Lab in Harlem on March 19, in order for them to get a better understanding of DNA, how it works, and why it’s considered the “molecule of life.”

A question that scientists are scrambling to find an answer to is “Where do we come from?” This lab helps us answer that question. By extracting our mitochondrial DNA (mtDNA), we can sequence it and see the evolutionary patterns and relationships that made us human. This can determine who our ancestors are.

First, the class received a review lecture by Austrian scientist Dr. Christine Marizzi, PhD about the origins of humans, the molecular clock, biotechnology, and basic information about DNA and how it works. DNA is the molecule solely responsible for giving a person traits, both physical and genetic. It is found in structures called chromosomes and there are 23 pairs of chromosomes in every cell in the body. For trillions of cells, that’s a whole lot of DNA!

“I enjoyed the review,” said Alec Gurevich ’14. “I recalled a bunch of essential information, including phylogenetic trees, DNA structures, and other topics that will be on the AP.”

After the lecture, the lab procedure began. In order to sequence a person’s DNA, it needs to be extracted first, and the students extracted their own DNA by swishing around water in their mouths and spitting it out. The cheek cells were extracted. After that, the cells (known as a pellet) were spun in a device called a centrifuge, so that it would be fully isolated from the rest of the saliva.

“It was interesting to have us spit into the cups,” said Gurevich. ‘14. “Although it was kind of gross, I felt like an actual scientist working in an actual laboratory.”

In order to extract the DNA from the cells, a series of pipettes were used to extract the molecule as finely as possible. Between the extractions, the DNA was heated and centrifuged multiple times in order for there to be no foreign body in the sample.

After the extraction, the DNA was separated through a process called gel electrophoresis, in which DNA fragments were separated and were easier to sequence. The results of the gel electrophoresis were obtained, packaged, and sent to a sister lab in Upstate, New York, where the DNA will be sequenced. In two weeks, students will be able to see the amino acid (protein) sequence of their DNA. With the sequence, they can compare it to those of other students to see who they are “more closely related to.”

“The trip as a whole was fun,” said Hillary Syeda ’15. “A lot of the material we discussed, along with the lab as a whole, was a good review of what we learned in class and will help for the upcoming AP exam.”

Ms. Ross said she will be taking more of her AP Biology students to the lab for the years to come as she feels this is a good review for the AP exam.

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