Science in Mind

Scientists debate, try stem cell acid test

A mouse embryo generated from STAP cells.
A mouse embryo generated from STAP cells.

Already, scientists in laboratories across the world have begun dipping mature cells in acid, hoping to see whether this simple intervention really can trigger a transformation into stem cells, as reported by a team of Boston and Japanese researchers in January.

At the Harvard Stem Cell Institute, a number of scientists have embarked on the experiment, which they’re informally calling “stem cell ceviche,” comparing it to the Latin American method of cooking seafood in lime and lemon juice.

The range of responses varies widely. Most scientists seem surprised and skeptical about the technique, but also impressed by the rigorous testing that experts in the field did on the cells. It appears that no one knows quite what to think.


Paul Knoepfler, an associate professor in the department of cell biology and human anatomy at the University of California, Davis School of Medicine, has been blogging about the discovery and polled his readers. In an unscientific survey that has drawn about 400 responses, he’s found that scientists are pretty evenly split on whether they are leaning toward believing in the technique or not.

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On Thursday, Knoepfler made his own opinion known. It is a harsh critique, starting with his view that the method is illogical and defies common sense. The biggest mystery may be why, if simple external stress can trigger cells to return to a stem cell-like state, it doesn’t occur more often in the body.

“Obviously, it has to be reproduced. That’s the caveat,” said Dr. Kenneth Chien, a professor in the department of cell and molecular biology and medicine at the Karolinska Institute in Stockholm. “I still think it’s shocking. And it makes me wonder if it’s true or not, it’s so shocking.”

We seem to have arrived at an unusual scientific moment. People have quite informed gut reactions, but lack solid evidence to show the technique does or does not hold up. It is exciting and nerve wracking; even many of those with doubts are not ready to dismiss it and even hope it is true. This is how science works: people turn to the experiments to smash or solidify their doubts.

One reason the finding is so unusual is that it pretty much blind-sided the scientific community. Often, researchers are aware of discoveries that will be published in their fields through informal channels. In this case, people were surprised. That is in part because one of the scientists pushing the work was far from an insider. Dr. Charles Vacanti is an anesthesiologist at Brigham and Women’s Hospital, not a stem cell scientist.


Notably, even though the team of researchers was partially based in Boston, where there are many leaders in the stem cell field, they turned to world experts in Japan to vet the cells.

Dr. Leonard Zon, a stem cell scientist at Boston Children’s Hospital, spoke from a meeting on cancer and stem cells in Canada, where everyone was talking about the work.

“It definitely has stimulated a lot of discussion,” Zon said. “I guess I’m not so sure. But it’s easy enough to do, so a lot of people will do it.”

Carolyn Y. Johnson can be reached at Follow her on Twitter @carolynyjohnson.