Cross-contaminated cell lines could be causing us to waste millions or more on flawed research. And many scientists don't even know it.

Flickr/Nathan Reading

Retractions of published work are regrettable, but they happen. Ivan Oransky, the executive editor of Reuters Health, highlights one involving a German researcher, Robert Mandic, who's in the business of studying head and neck cancer. Mandic's lab results were invalidated last year when he discovered that the cancer cells he'd been working on were actually descended from a cervical tumor -- not the rare head and neck cancer he thought he was studying.

The journal that initially published Mandic's paper wound up dropping the work, but not for the reason you might suspect:

The scope of Oral Oncology covers only head and neck cancers. As the findings of this paper no longer refer to a cell line that is implicated in these tumours, the paper has been retracted from the journal, since it would not have been acceptable for publication during peer-review based on the information now available.

In other words," Oransky writes, "the real reason the paper is being retracted isn't because the results were no longer valid, but that they were no longer valid for a head or neck cancer."

Mandic's story is part of a front-page article in The Wall Street Journal today (login required) warning about the dangers of contaminated cell lines -- the samples that researchers use for performing lab tests. Cell lines typically begin with a single donor whose disease has learned to replicate indefinitely, providing researchers with a never-ending supply of test subjects.

Cell lines are extremely useful, but they can also cause major headaches when they get mixed up. One of medicine's most famous cell lines is known as HeLa, which is a portmanteau of the name Henrietta Lacks. Lacks had a type of cervical cancer that led to her death in 1951, but her cancer cells were preserved and have since been used in studies involving everything from polio to sex hormones. Unfortunately, due mostly to human error but helped along no doubt by the cells' natural resilience, HeLa cells have been implicated in more than a hundred cell line contaminations over the years.

This is a costly business. The worst part is, nobody can say for certain how many studies have been affected by misidentified cell cultures, or how much money has gone down the drain because of them. We can only guess at it. Some believe that as much as 20 percent (!) of all published work involving human cells may have used bad cell lines. And it's not talked about, both because of the strong industry pressure to publish and because of a simple human reluctance to admit failure.

That's not to say there have been no attempts at bookkeeping. In 2010, an international team of researchers produced a list of more than 350 known misidentified cell lines. The list fingered HeLa as the contaminant in 29 percent of the human samples.