Genetic Analysis of 250 Burgers Reveals Some Unsavory Surprises

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Last year, a biotech startup called Clear Labs performed DNA testing on a bunch of hot dogs and discovered that they often contain more than the label advertises. The same company has now used its arsenal of molecular technologies to break down America’s other favorite meat-on-a-bun product: burgers. Once again, there are some unsavory surprises.

Clear Labs’ latest report—which included genetic and nutritional analyses of 258 samples of meat and veggie burgers—discovered “significant issues” in 14 percent of products. These included substitution of ingredients, glaring deviations from nutritional labels, several instances of food-borne pathogen DNA and rat DNA as well as one case of human DNA. Some of these findings should raise real concerns; others are the unappealing but inevitable consequence of using genetic sequencing technologies on lots and lots of products.


Clear Labs, a Silicon Valley startup that bills itself as “the world’s first food analytics platform for retailers and manufacturers,” has developed a next-generation DNA sequencing pipeline that can take any food item and deconstruct it into plant, animal, bacterial, and fungal ingredients. As I’ve reported previously, the analysis is semi-quantitative, meaning the company can say if an ingredient is present in trace amounts (as was the case for rat, human, and pathogen DNA) or if it constitutes a major substitution.

Trace ingredients are a hygiene and cleanliness issue, however. The presence of human DNA in just a single frozen veggie burger does not mean there’s something terrible going on at the bean burger plant. More likely, it means a person handled a sample without gloves before it went through Clear Labs’ pipeline. The same goes for the rat DNA that was present in just three samples. Yes, it sounds disgusting, but it almost certainly points to an unclean factory rather than a deliberate deception.


On the other hand, Clear Labs did find several instances in which burgers were “adulterated” with a significant amount of an unlisted ingredient—lamb or bison burgers that were laced with beef or chicken, for instance. The analysis also found one black bean burger that contained no black beans whatsoever, and 14 other veggie burger products that were missing an ingredient listed on the label.


“We were super surprised by the higher rate of problems in veggie products, because you normally think of veggie products as being safer” Clear Labs co-founder Mahni Ghorashi told Gizmodo. Ghorashi added that in addition to substitution issues, veggie burgers were more likely to contain snippets of DNA from known human pathogens. Overall, Clear Labs found evidence of bugs that cause illnesses including gastroenteritis and pneumonia in 12 samples.

But other experts caution that these pathogens may not be a real issue.

“The biggest concern, and they mention this in the report, is that the method cannot differentiate between live and dead cells,” said Michael Doyle, a professor of food microbiology at the University of Georgia. “The cooking process will kill most pathogens. I think their results may be a bit misleading in that sense.”


Clear Labs’ new report is salient given recent revelations of rampant substitutions in the seafood industry, and scandals including Ikea’s legendary horse-flavored meatballs. If genetic testing—which is rapidly becoming cheaper and more reliable—can help hold the meat industry accountable, then regulators should consider making it an industry standard.

Other aspects of Clear Labs’ analysis will require further refinement before they’re useful. Finding pneumonia DNA in a burger sure sounds awful. But whether this discovery is fodder for anything more than a media scare-fest remains to be seen.