Mass Spec Method For Safer Pufferfish

People who eat puffer fish—also known as fugu—take their lives in their own hands. These fish contain tetrodotoxin, a powerful neurotoxin that can spoil a good meal and even kill the diner. The edible portions of the fish vary by species, and some species aren’t edible at all because the toxin is too widespread. Because of the potential danger, Japanese law requires that puffer fish be labeled by species. And in the U.S., only one species of puffer fish is legal. In an effort to improve food safety, researchers at the National Research Institute of Police Science, in Kashiwa, Japan, developed a liquid chromatography/mass spectrometry method to genotype 12 puffer fish species (J. Agric. Food Chem. 2015, DOI: 10.1021/acs.jafc.5b03703). Hajime Miyaguchi and coworkers used the polymerase chain reaction to amplify specific sequences from the mitochondrial genes for each species’ 16S ribosomal RNA. They then digested the amplified DNA and analyzed it with high-resolution LC/MS. The researchers were able to distinguish all species, except for two puffer fish that have the same sequence.