Giving Genotypes a Glow

School News
May 2, 2018- Just ten years ago, the genetic testing equipment that is being used in Ross Sappenfield’s Upper School science class at VMS would have been part of a multi-million-dollar high-tech startup company. It’s called Polymerase Chain Reaction (PCR) and it’s essentially a futuristic DNA photocopy machine. 



“We’re able to put in a highly engineered chemical that can isolate a specific gene,” explained Sappenfield, VMS Science Department Chair and Upper School Science Teacher. “We then mix that in with a small sample of cells from your cheek, put it in the PCR and it makes about 17 trillion copies of that specific segment of DNA in 30 minutes.”

In one experiment, students probed their own DNA, testing their genes to examine whether they are genetically oriented to be morning or night people. They first swabbed their cheeks, mixed that sample in a small vial with the isolator chemical (known as a DNA probe), thrust those vials into the PCR and sat back to watch as the mysteries of their genetic sleep dispositions unraveled. When the machine was finished, the samples came out, and, using highly accurate micro pipettes, they added a marker dye so they could see the now-amplified DNA.



“After the marker goes in, the DNA all glows bright blue,” Sappenfield described. “It’s really cool, and very photogenic.” A picture of mad science – iridescent test tubes and electric pipettes – the perfect experiment to pique a budding researcher’s interest in DNA. 

Despite the dazzling display, though, technology of this caliber can be difficult to decipher. 

“The sleep study went well,” said Sappenfield. “They were really interested in it, but it’s still challenging to interpret the results.” Sappenfield explained that some students who self-identified as night-people discovered that, according to their genome, they were actually morning-people. 

“So, it doesn't always match up to what they think it should be. Which, is also a good conversation to have,” said Sappenfield. “Your genotype doesn't necessarily determine your phenotype all the time.”

The Upper School science classes won’t just be testing for sleep proclivities, either. Sappenfield has some other exciting plans for how he’s going to put this technology to use. 



“We can also actually test any food to see if they have been genetically modified.” He explained excitedly. “I have a DNA probe that can find the genetic code that’s used for modifying organisms and we can to determine if this kind of food is a GMO or not.”

He’s also planning on doing a test for taste genes – the ultimate update to the classic PTC paper experiment. Only about 75% of people can taste the insanely bitter chemical, PTC, and Sappenfield plans on using VMS’s new genetic testing equipment to bring that time-tested lesson to life. By first testing the student’s phenotypes with actual PTC paper, and then, testing their genotype with the PCR, students will have a tangible encounter with their own genetic code. 

“It gets them to think about what their genes really mean, and how their genes express themselves.”

The PCR’s capacity for experimentation doesn't stop at genetic testing, either. This technology can also be used for protein analysis – which could make for some fascinating lessons in food safety and even advertising. 

“There’s been some controversy about sushi sashimi not really being what it is advertised and sold as,” said Sappenfield. “We can test that too, with Gel Electrophoresis. That’s not DNA testing, that’s protein testing, but it uses the same process.”



PCR first hit research labs in 1983. At the time this was a groundbreaking, game changing scientific technique, and in the years since it has become indispensable for clinical and research laboratories. It’s used commonly for DNA cloning, gene manipulation, gene mutagenesis, amplification of ancient DNA, and much, much more.  

“It’s really powerful,” said Sappenfield. “I can’t imagine doing this in a high school environment even ten years ago.”



For students to be exposed to such high-tech science in high school – technology that many don’t encounter until they are actually inside of a bona fide research laboratory – is not only impressive, but inspiring. It could spark an interest in any number of different professional fields: from biomedicine, to criminal forensics, historical forensics, genetic mapping, genetic modification, and disease detection and prevention. 


This story was contributed to VMS News by freelance writer, Will Brendza, working in collaboration with the Vail Mountain School Advancement Office.