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As Molly Herring reports, there’s trouble in labs around the U.S. Scientists are struggling to figure out why—and how—the standard growth medium is disrupting their studies. For now, it’s simply a problem; but as Herring suggests, it could lead to an exciting new discovery…

Reine Protacio couldn’t figure out why all her cells kept dying. A molecular biologist at the University of Arkansas for Medical Sciences College of Medicine, she kept trying to grow colonies of fission yeast (Schizosaccharomyces pombe) on petri dishes plated with nutrients. The lab uses the microbes to study what happens to DNA during cell division, but even in the control experiments, none of the yeast survived. Protacio and her colleagues investigated several possible suspects—from dirty glassware to contaminated water—before landing on a surprising culprit: bad agar.

Derived from seaweed, agar is a gelatinlike ingredient used to grow yeast on a solid surface. It’s like flour in cake batter, Protacio says. “You’d never expect the flour—it’s the most basic thing.” And yet here was agar, foiling day after day of experiments. As is turned out, Protacio’s lab wasn’t alone.

When Protacio first identified the bad agar last summer, one of the heads of her lab, molecular biologist Wayne Wahls, posted about the find on a community email group called PombeList. Labs on entirely different continents responded that they faced what seemed like the same problem, even though their agar had come from different companies and lots, sometimes years apart.

Nick Rhind, a cell biologist at the University of Massachusetts Chan Medical School, reported his lab had received a toxic batch of agar as far back as 2006. He had sourced his supply from the same company that sold bad agar to Protacio’s lab: Sunrise Science Products.

The problem probably didn’t arise there, Rhind says. Sunrise and other lab supply companies don’t manufacture the agar themselves; they buy it from other firms that make it from two polysaccharides—agarose and agaropectin—found in the cell walls of red algae, a kind of seaweed. “My understanding was that there were very few suppliers,” Rhind says. “Everyone pretty much bought it from the same bulk supplier, packaged it, and sent it out.”…

[Herring unpacks the efforts to figure out what’s going wrong…]

… Getting to the bottom of the issue might be more trouble than it’s worth, however. Purifying and identifying an active compound is a long and complex process of elimination, Rhind says. For the time being, he says, labs and suppliers should take extra steps to avoid contamination wherever possible. This could include more thorough quality control tests using many different formulas and microbes. “I don’t think anyone is that interested in why the [yeast] died,” he says. “They just want to make sure it doesn’t happen again.”…

But that could be an opportunity lost…

[One] possibility, Rhind says, is that the red algae, other algae growing on it, or even bacteria eating the algae produce an antifungal compound, which would kill yeast. If so, a nuisance for microbiologists could be a boon for drug developers. “There are actually not that many good antifungals in the world,” he says. “It would be a serendipitous discovery, but it’s a long shot.”…

Dissipating dark clouds– and searching for silver linings: “Bad agar is killing lab yeast around the world. Where is it coming from?” by @mollymherring in @ScienceMagazine.

* Alan Gregg

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As we muse on media, we might spare a thought for Virginia Apgar; she died on this date in 1974. A physician and medical researcher, she is best remembered as the creator of what’s now known as the 10-point Apgar Score, a way quickly to assess the health of a newborn child immediately after birth in order to combat infant mortality. Given at one minute and five minutes after birth, the Apgar test measures a child’s breathing, skin color, reflexes, motion, and heart rate. As colleague observed, “she probably did more than any other physician to bring the problem of birth defects out of back rooms.” 

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