NIIGATA -- What exactly is the polymerase chain reaction (PCR) we keep hearing about being used to test for the coronavirus? To try to answer this question, a group of 10 first- and second-year high school students in central Japan's Niigata Prefecture took part in specially organised biology experiments.
The PCR process uses the enzyme polymerase, which can produce a chain reaction in which DNA is reproduced and increased. The enzyme has been a tool in DNA analysis since the 1980s, but its role in testing for the coronavirus has catapulted it to fame.
Students at Kamo Gyosei High School in the city of Kamo, Niigata Prefecture, tried out the experiments. According to the science teacher behind the plan, it was conceived to "get students to understand the principles of polymerase chain reactions, and encourage them to take an interest in areas like genetic editing and new drug development."
Because completing the experiment during a normal 50-minute lesson would be difficult, it was performed across about six hours during the spring break, as part of education support lessons held for staff development. The lesson reportedly offered a very practical level of content for high school students.
In all, four second-year students studying nursing, five second-year students in the general division's quest course, and one first-year student in the same division's sports course took the class. Two third-year students from Niigata University of Pharmacy and Applied Life Sciences, based in the city of Niigata's Akiha Ward, also participated as assistants.
First, their teacher gave them an explanation of the structure of DNA, and the principles behind PCR. Then they split into groups of three or four to start the experiment.
Students ground down cabbage, broccoli and other vegetables, from which they extracted DNA. After adding reaction solution, they placed the samples in thermal cyclers and caused a polymerase chain reaction, creating samples of genetic material each about 1 centimeter long.
Voltage was then applied to the samples, and the DNA split and moved in accordance with its length. The students then measured the distance the DNA had moved against a scale, and confirmed that vegetables with similar lengths of DNA were of the same species.
Shiori Hirata, a second-year nursing student, aged 17, said, "I took part because I wanted to know what PCR is. It was difficult, but I'm happy we got results." There were some unsuccessful groups, but their teacher said, "I hope that their first experience with PCR will help them see its difficulties and joys." The school plans to periodically expand upon the PCR biology experiments and genetic modification tests, among other science initiatives.
(Japanese original by Mayuka Ikeda, Niigata Bureau)