The sandwich chain Subway is facing a class-action lawsuit in California over whether the meat in its tuna sandwich is in fact tuna, prompting Julia Carmel at the New York Times to purchase sandwiches for PCR analysis.
In January, the Washington Post reported that the chain of stores was being sued for fraud and other claims. The suit alleges, according to the Post, that testing of the tuna wraps and sandwiches found they are "a mixture of various concoctions that do not constitute tuna yet have been blended together by defendants to imitate the appearance of tuna." As the Post reported then, Subway says the claims are without merit and that its sandwiches contain wild-caught tuna.
The Times' Carmel sent off "60 inches worth of Subway tuna sandwiches" from around Los Angeles for testing at a commercial lab. That PCR test, she writes, was unable to find tuna DNA, which could mean either that there was no tuna or that the processing made it too difficult to identify tuna DNA. If there was a fish swap, experts tell Carmel the change was likely at the cannery, rather than sandwich shop level.
In a statement, Subway says that the testing "does not show that there is not tuna in Subway's tuna. All it says is that the testing could not confirm tuna, which is what one would expect from a DNA test of denatured proteins."