Culver students learn CRISPR, develop strong base of knowledge about DNA technology

While students at some high schools learn about gene editing technology such as CRISPR in theory, students at Culver Academies do actual hands-on lab work involving gene manipulation.

Students taking Molecular Biology learn how recombinant DNA technology is used to manipulate genomes, including CRISPR-Cas9 system.  This is an immune response bacteria use as a defense mechanism against viral infections. Scientists can use this system to make precise cuts in human DNA and insert a DNA sequence of interest.  This system allows scientists to make changes in DNA of living cells easier and cheaper than before.

“This is next level science. I didn’t expect to see how easily a gene could be manipulated by just inserting bacteria into the food that they eat,” said Juan Urruela ’25. “It was certainly different from a textbook class.”

The students learn how to edit genes using enzymatic reactions that are too small to be seen through a microscope, working with 1/1,000^th of a milliliter, said senior science instructor Jessica DeNapoli, Ph.D., who developed the class six years ago.

“They end up with a bacteria that is producing something from a mouse’s gene, which they never were able to do before,” DeNapoli said. “It’s a cool concept.”

Master instructor Kristine Myers ’75, who teaches the one-term class, said molecular biology is a rapidly expanding field because of its critical role in dealing with global health challenges. It offers a potential cure for genetic diseases such as sickle cell anemia, cystic fibrosis and others.

“The DNA mutation in these diseases is very small. If you can go in there and fix that code you now have a cure for that genetic disease,” she said. “Now with CRISPR, we have a potential cure. That’s incredible.”

Students at Culver begin learning about cellular structure and function, DNA and genetics in introductory biology class which is a prerequisite for Molecular Biology.

The Molecular Biology class, comprising mainly seniors and first classmen, teaches advanced laboratory skills beyond what they learn in the introductory biology course.   

 

 

“Sometimes we have two labs going on at once and at the end of the term we might have three. We’re finishing one up, they’re in the middle of another one and then they’re beginning the third one,” Myers said. “By the time they leave this class their lab skills are very well developed.”

Students then take part in a series of laboratory activities where they learn to transfer genetic material from eukaryotic organisms, which includes all animals, plants, fungi, and unicellular protists, to bacteria like E. coli.

“We isolate a gene and we utilize recombinant DNA technology to insert it into the bacteria,” Myers said.  “Then the bacteria use the DNA code of that gene to produce the protein the gene codes for.” 

She explained that this is how insulin is made in the lab.

“Students need to be precise in their measurements.  They mess up sometimes, but so what? They’re learning,” Myers said.

Students eventually learn to use RNAi (RNA interference) to manipulate the expression of genes in C. elegans worms, microscopic nematodes found in the soil and a model organism for research.  A student asked if the worms feel pain during the experiment. DeNapoli explained they can’t feel pain because they don’t have a central nervous system.

Students prevent specific proteins from being made by feeding C. elegans altered bacteria, which can change how they move or look.

“This is not something you get to do in your typical science class,” Urruela said. “I like that it is a high-level, hands-on class.”

When they get to CRISPR, a two-day lab, the students are changing the DNA of either yeast or bacteria, depending on how much time they have at the end of the term.

Bacteria produce an enzyme that processes sugar. The students make a mutation in the DNA sequence that codes for this enzyme, so the enzyme is no longer functional and the sugar can’t be processed by the bacteria.

“It actually causes the bacteria to change color from a whitish-yellow to blue. So students can figure out if it worked or not by looking at the bacterial colonies.  It helps them get the concept without targeting any gene that might be dangerous,” DeNapoli said.

Myers said what makes this class even more timely is recent news reports that a company has genetically engineered three wolves that resemble extinct dire wolves.  Myers said because of that she added another lab this year.

“Because students were asking about it,” she said. “People should understand it.”

Myers points out that scientists didn’t actually re-create a dire wolf.

“They do have dire wolf DNA and sequenced their genome.   They then inserted certain dire wolf genes into the grey wolf genome that gave these three gray wolf pups the characteristics of a dire wolf.” 

Part of the class is teaching student ethics.  CRISPR has raised ethical questions about altering human DNA and while Culver students aren’t working with human DNA, there are still ethical questions.

“There’s a lot of responsibility that comes with having this knowledge,” Myers said.

DeNapoli also points out there are a lot of regulations involved in getting the materials needed for the class.

“We couldn’t purchase all of the materials we need to do this if we weren’t certified as an academic institution,” she said.

Kate Clemons ’26 said it was her favorite science class.

“It’s a lot easier to understand because you are doing experiments in a lab because it’s easier to grasp when you see it change color or you see a worm has bumps on its skin,” she said.

Urruela said he enjoyed the class.

“It gave me a real glimpse into how science works. It was not just about knowing the facts, but how the science works,” he said. “It was challenging, but in a good way.”