Salmon science: Diving into a fishy field

Salmon sperm in the strangest placesSalmon DNA has been getting the celebrity treatment recently, with saturation coverage in People and similar magazines of stars and influencers who purport to use polynucleotide fragments from fish sperm to maintain a youthful glow.“Now, has it been FDA [US Food and Drug Administration] approved for injection? No. Is everyone using it kind of off-label or nonapproved? Yes,” says Azza Halim, a physician-anesthesiologist who runs a medical spa in Boca Raton, Florida, whose offerings include salmon sperm DNA microinjections. But the treatment’s status hasn’t made a difference in its popularity, Halim adds. “Everyone's talking about injecting it.”When a pitch about this frankly weird new cosmetic procedure landed in the Newscripts inbox, it prompted a collective reflection on other strange places C&EN staff have encountered salmon sperm DNA: as a blocking reagent for DNA hybridization methods, a carrier DNA for transfection, a substrate to measure the strength of compounds’ nonspecific DNA binding, and even a battery stabilizer. But whatever the chemical questions they answered, these experiments all failed to address one mystery: Why salmon?Queries to purveyors of salmon sperm DNA lamentably went unanswered. Instead, Newscripts found its most authoritative answer deep in the archives of the Mad Sci Network, a forum from the days before widespread Google use. In 2001, Matt Champion, then a graduate student at Texas A&M University, wrote that because most researchers don’t study salmon, its genetic material is unlikely to match a researcher’s probe for a human, mouse, or fly gene. Also,