Two teenagers checked 60 samples of seafood in restaurants using a simplified genetic fingerprinting technique to see whether the fish New Yorkers buy is what they think they are getting. They weren’t.

Although the testing technique is at the forefront of research, the fact that anyone can take advantage of it by sending samples off to a laboratory meant the kind of investigative tools once restricted to Ph.D.’s and crime labs can move into the hands of curious diners and amateur scientists everywhere.