Researchers studying microbiomes can do their best to prevent contamination, but a new study reveals widespread, low-level contamination in DNA extraction kits. Reporting in BMC Biology today (November 11), Alan Walker of the University of Aberdeen in the U.K. and colleagues list dozens of contaminating taxa that can swamp out a sample’s true microbial signal, if starting concentrations are low.
“It’s really important to sequence a negative extraction control,” said Patrick Schloss, a microbiome researcher at the University of Michigan who did not participate in this study. “That’s something people should be doing and are not doing.”