TV News Crew Reports on Classroom Study of Seafood DNA

A news crew from NBC 5’s consumer investigation unit visited a DU classroom last week to learn more about a lab experiment that aims to reveal if labels placed on a variety of fish types accurately reflect the type of fish being purchased.

In Dr. Irina Calin-Jageman’s molecular cellular biology course (BIOL 352), students learn how to isolate mitochondrial DNA from a variety of uncooked fish samples for sequencing at a lab in Wheeling. The DNA sequencing can determine if the fish really is what the restaurant or grocery store labels indicate.

“Every year, depending on the class and the samples, we find that 10% to 30% have been mislabeled,” Calin-Jageman said.

The most commonly mislabeled fish is red snapper, which often turns out to be tilapia, a less-expensive fish, she said.

Calin-Jageman was inspired to bring this lab exercise to the classroom several years ago after an investigation by Oceana, an international advocacy and conservation organization, found that one-third of more than 1,200 seafood samples tested between 2010 and 2012 across the United States were not what their labels said they were.

The students in Calin-Jageman's class purchased seafood of their choice from restaurants and stores in their communities. In the class the NBC 5 team visited on Oct. 3, there were more than 20 fish samples being prepared for DNA testing, including salmon, cod, yellow tail, sea bass, swordfish, red snapper and more. 

The work done by the students follows the same protocols as FDA labs, Calin-Jageman noted.

“It's really interesting to participate because it reminds me of watching experiments like this on Animal Planet or Nat Geo Wild as a child," said senior Ethan Velasquez, a biology major. “I always thought I wanted to do this, so I'm glad I have the opportunity now.”

Senior Lesya Davis, majoring in natural sciences, said she was hopeful the catfish sample she brought to class was, indeed, catfish, because she enjoys eating it.

“I would have thought it's fairly easy to determine what fish is which—until I got here and learned there's a lot to go through to figure out what we are actually catching,” she said. 

The NBC 5 crew is expected to return to campus in a few weeks when the results of the DNA testing are in. Their report is anticipated to run in November.

The work performed by the students will also be shared during next spring’s Science and Ideas Expo.