Brenda Tan and Matthew Cost, high school seniors from Trinity School in New York City, used a technique called DNA barcoding to find out what species were present in over 200 animal products. Their extracurricular experiment, which they completed with the help of Mark Stoeckle, of The Rockefeller University, suggests that buyers should beware! shot, produced by flora lichtman. music by Knife Crazy. cover shot by Ralph Hockens/flickr.