Decoding DNA in Class 9

DNA, often called “the blueprint of life,” holds tremendous promise for understanding heredity, solving crimes and extending lives. Thanks to a longstanding partnership with the distinguished Cold Spring Harbor Laboratory, Chapin students have the invaluable opportunity to learn about this fascinating area of science from real-world geneticists.

National DNA Day recognizes the completion, in 2003, of the Human Genome Project, the international research endeavor that determined the DNA sequence of the entire human genome. Chapin celebrated this extraordinary milestone through an immersive, all-day activity that allowed Class 9 students to step into the roles of genetic engineers.

Placed in three rooms (501T, 502T and 600), the students were assigned to one of the instructors from Cold Spring Harbor’s DNA Learning Center: Elna Carrasco, Melissa Lee and Keil Thomas. Although their teaching styles differed, the lessons they oversaw – and the passion and expertise each displayed – was equally engaging. Under their guidance, the students used actual DNA to conduct an enlightening experiment called “Bacterial Transformation.”

“We’re going to give our bacteria a new piece of DNA,” said Mr. Thomas to his group. Intriguingly, the DNA for this experiment came from Aequorea victoria, the Pacific jellyfish, found off the West coast of North America. Also known as “crystal jelly,” this organism is a bioluminescent hydrozoan jellyfish. In other words, it glows naturally. 

DNA strands, the thread-like chains of genetic information all organisms possess, code for the making of proteins that determine traits, known as genes. Plasmids are small circular pieces of DNA that replicate independently from the host’s chromosomal DNA. Pacific jellyfish, for example, contain Green Fluorescent Protein (GFP). In this experiment, the students worked with GFP plasmid or pGFP. The bacteria called for was mm294 E. coli, a completely harmless strain often favored by scientists because it reproduces rapidly and is easy to culture. 

Collaborating in teams, the students tackled each step in the scientific process with energy and determination. With no pressing time constraints, they were free to proceed at their own pace. The overarching goal of this experiment? To implant the jellyfish’s DNA into the DNA of an ordinary mouse, causing it to glow green. “Lighting up” tumors and other maladies in the mouse’s body would make them simpler to detect, helping to advance medical research.

In each room, equipment surrounded the students -- beakers, test tubes, petri dishes, a centrifuge machine, a Poly Pro warm-water bath, buckets of ice and enough goggles and gloves to go around. After each instructor introduced the fundamentals of genetic engineering with lively presentations and practical demonstrations, the young scientists were off and running.

With one test tube labeled (-) and the other (+), they added calcium chloride to each, followed by a clump of the E. coli. After spinning their tubes in the centrifuge machine, they added pGFP to the (+) tube only, then placed both tubes in ice-filled beakers for 15 minutes, following by a quick warm-water bath.

After several more steps, the students distributed the protein-enhanced bacteria throughout petri dishes, which had been coated with a special gel, being careful not to expose the samples to too much air or touch them with their gloves hands. Finally, the dishes were secured with masking tape, labeled and stored upside down. The following week, the students and instructors would gather together again to see if the jellyfish protein was in fact being made in the bacterial colonies, indicating a successful experiment.

All day long, each of the science rooms buzzed with activity and the excitement of discovery. The students enjoyed using the centrifuge machine, which separated the DNA by rapidly spinning tubes inside a metal cylinder. Many were eager to operate the pipettes, slender, syringe-like items intended to measure out precise quantities of liquid.  They all pushed themselves to accomplish the challenging steps in this experiment, staying focused and engaged throughout.

For Class 9, DNA Day proved to be incredibly valuable. “We’re so grateful to the staff of Cold Spring Harbor Laboratory’s DNA Learning Center. The day was a wonderful opportunity for our students to explore more about DNA and conduct longer experiments than a normal class period would allow,” commented Upper School Science teacher Lacey Friedman, who organized the day’s activities.

Guided by Cold Spring Harbor’s outstanding instructors, the students in Class 9 have developed sophisticated scientific skills and knowledge that will serve them well throughout their years in Upper School and beyond. Perhaps some will become genetic engineers one day.

Browse photos from the classes below: