By Brian Seetoe ’19 and Vasyl Ilnytskyy ’19
The Advanced Placement (AP) Biology class, taught by Ms. Jessica Ross, went on a trip in order to further their studies on DNA (deoxyribonucleic acid) by getting hands-on experience at the Harlem DNA Learning Center (DNALC).
Students were given the opportunity to perform a lab where they sequenced their own DNA to discover how closely related they are to each other.
“The College Board has a number of required labs and this was one of them,” stated Ms. Ross. “The material they covered will be tested on the AP exam in May.”
Although the exam is some time away, labs such as this one retain their importance and may even help students due to their heavy reliance on hands-on activities which have been found to acutely increase the students understanding of scientific concepts as concluded by a study led by the University of Chicago.
According to the Harlem DNALC website, “This lab examines Single Nucleotide Polymorphisms (SNPs) in the human mitochondrial genome. Students amplify a small region of their own mitochondrial DNA and use the product as a template for DNA cycle sequencing. The students obtain their ‘finished’ sequence and perform computer analysis of the data using the DNALC’s online bioinformatics tool Sequence Server.”
In order to extract the SNPs, each student had to begin by swirling a nine percent saline solution in their mouth for a minute in order to extract cheek cells which contain the DNA they are going to use as their template.
“The saline solution was clear, and it tasted like nothing at first, but it became salty by the time we spit it out. It felt weird,” stated Joann Mei ’19.
The students then used a process called Polymerase Chain Reaction, PCR for short, to make many copies of DNA and make samples to put into a thermocycler for 40 minutes which would separate the DNA into individual strands, cloning each strand, making double the number of strands as before. The samples are then put into a centrifuge which separates the strands into groups, making it easier to put the DNA into the gel electrophoresis, the process during which DNA fragments are separated using an electric current where the DNA fragments can be easily seen and compared.
“Overall it was a very good experience and a lot of people were able to conduct lab techniques such as gel electrophoresis for the first time,” said Vasilisa Tolkacheva ’19. “It was a bit nerve-wracking because once you pierce the gel, your sample is gone forever, hence people were a bit nervous for this part of the lab. However, the lab instructor was kind enough to redo the lab for people that lost their samples in the process.”
Aesam Sharafaldin ’18 stated, “I think it’s very interesting because genetic sequencing could provide new information on the genetic basis of poorly understood diseases with the potential to provide new therapies.”
Ms. Ross said, “It’s nice to see the kids doing real science and extracting their own DNA.”
The class will be getting their results at the end of April when they can finally compare their DNA to see how similar their DNA results are to not only their classmates, but also to different populations across the world and other species of animals.
Rreze Kadrijaj ’19 contributed to this article.