GoKawiilThe β-galactosidase molecule can be targeted by antibodies in experiments. But some studies have erroneously used the antibody that targets the bacterial β-galactosidase instead of the mammalian version.Credit: Laguna Design/Science Photo Library
More than 50 studies on cell ageing have apparently used the wrong antibody to identify a key protein in experiments, according to a science sleuth.
The latest case comes two months after Sholto David, a UK-based independent molecular biologist, identified hundreds of studies with a similar error and three months after he and another researcher spotted problems with antibody-validation images in the catalogue of one of the world’s largest suppliers, Thermo Fisher Scientific, headquartered in Waltham, Massachusetts. David reported the latest antibody mix-up in a 21 July post on the research-integrity blog For Better Science. It’s not clear whether the flaws compromise the studies, but David says they might in some cases.
Antibodies are a workhorse of biological experiments because they bind to and track specific proteins. But they are also a source of many problems. In some cases, researchers struggle to replicate experiments despite using identical antibodies. In other instances, the antibodies recognize other proteins, as well as the ones they are sold to detect, creating unreliable results.
In the latest case, David says that researchers seem to have chosen the wrong antibodies — instead of using ones that target mammalian proteins that are thought to reveal information about ageing, their papers listed antibodies that bind to bacterial proteins. This highlights a larger problem in biology, in which reagents in experiments are used poorly or not adequately characterized, says Aled Edwards, a biochemist at the Structural Genome Consortium in Toronto, Canada. In an ideal world, he says, researchers would validate the antibodies, to check they work as planned, before starting an experiment. But this can be time-consuming and expensive, he adds.
He thinks the issue will get worse as more researchers use artificial-intelligence models to review the literature and make predictions about which proteins could be good targets for disease treatments. If the wrong antibodies are reported in papers, it could throw such predictions off, he adds.
Cell-ageing studies
Researchers studying ageing use an antibody to identify when cells stop dividing but remain alive — a state called senescence. Scientists want to understand this process because non-dividing cells accumulate in tissues, causing inflammation and secreting proteins that can harm nearby cells.
A hallmark of senescent cells is the activity of an enzyme called β-galactosidase. By using a mammalian antibody that binds to β-galactosidase, scientists can detect the protein using imaging techniques such as immunostaining or western blotting, and in doing so, theoretically identify senescence. (There is some dispute about whether this technique can accurately flag cells in senescence, but some researchers still use it.)
However, David says that he has identified at least 54 papers where the authors state they used an antibody that targets β-galactosidase from Escherichia coli bacteria. Using this antibody to try to identify β-galactosidase expression in mammalian cells is not going to work, says David. “This is a big blunder,” he writes on the blog.
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