What’s Poisoning These Scientists’ Lab Experiments?

Final 12 months, in July, Reine Protacio’s experiments out of the blue stopped working. Each scientist encounters baffling outcomes sometimes; you chalk it as much as error, repeat the experiment, and hope for the perfect. However on this case, the issue didn’t resolve and actually unfold to different members of the lab: Their yeast, which usually multiples with such intense fecundity that 500 colonies may bloom throughout a single laboratory dish, had change into stunted. Now they had been getting simply two colonies, perhaps three—lonely white dots in a sea of nothing. It was as if one thing was poisoning the yeast.

After two straight months of failed experiments, Protacio went searching for a perpetrator. Her lab as soon as had a defective water air purifier, so she switched the water supply. No distinction. She systematically changed the sugar and different vitamins for rising yeast. No distinction. The thriller, she ultimately realized, ran deeper and wider than she thought. And when she and her colleagues on the College of Arkansas for Medical Sciences began sharing her findings, a number of scientists all over the world reported comparable tales of ruined experiments. The circumstances all pointed to the identical suspect: agar.

Agar is and has been a staple of microbiology labs for a century. “We purchase it in bulk. We purchase kilograms at a time,” Protacio advised me. Blended with water, the seaweed-derived white powder varieties a sturdy, clear gel good for rising microbes. In my very own transient foray into the laboratory as an undergrad, I poured agar into most likely a whole bunch of petri dishes, a tedious however essential first step for a lot of experiments. The lab the place Protacio works makes use of agar to develop mannequin organisms referred to as fission yeast, whose chromosomes have hanging similarities with ours. The unhealthy agar derailed their experiments for 2 months. Though the lab may recoup the price of the agar, she mentioned, “they’ll’t reimburse us for the misplaced time and the misplaced productiveness.” So the lab began elevating the alarm.

In February, Wayne Wahls, who co-leads the lab the place Protacio works, wrote to an electronic mail record of fission-yeast scientists asking if anybody else had encountered comparable issues. One researcher replied sure, after which one other. A biologist in Massachusetts even had this agar downside method again in 2006. The extra that Wahls, Protacio, and a rising group of different scientists spoke publicly about the issue—in a preprint paper, then an article in Science—the extra tales they began to listen to. A couple of of the  scientists joined a examine of the agar as collaborators, and the preprint has since been submitted to a journal.

The total sample of agar failure that emerged is complicated, although. The issues in agar appear to have come and gone not simply as soon as however a number of instances, sporadically, through the years—suggesting shocking variability in an ordinary lab product. In addition they appear to fade beneath sure circumstances: when petri dishes are saved at nighttime, in keeping with one lab, or when yeast are fed a nutrient-rich weight loss plan, in keeping with Protacio’s personal work. Dawn Science Merchandise, the corporate that provided the seemingly poisonous batch to her lab, advised me it’s been capable of efficiently develop fission yeast on the identical batch of agar. “Please perceive that we’re NOT disputing their findings of their experimental state of affairs,” the CEO, Liz Kylin, wrote in an electronic mail. Maybe the issue exhibits up solely in sure batches and beneath sure circumstances, which Dawn remains to be making an attempt to grasp. “No matter this situation seems to be, it’s actually elusive, most likely extraordinarily particular,” Kylin wrote.

Scientists have began to surprise if the potential toxicity originated within the seaweed used to make the agar. That would clarify the variability from batch to batch: Maybe sure components—ecological, meteorological—alter the biochemical make-up of seaweed, the identical method a wheat harvest differs from season to season and wine grapes range from 12 months to 12 months.

Agar can also be utilized in meals, significantly in desserts in Asia. (Protacio is from the Philippines, and she or he initially knew agar as an ingredient in sago at gulaman, a cool, candy drink that always accommodates bits of agar jelly.) And laboratory agar really has its origins in meals too: Within the Eighteen Eighties, Fanny Hesse advised that her microbiologist husband use agar in his work, as a result of she had used it to set fruit and vegetable jellies; her mom had heard about it from pals who had lived in Java. At present, nonetheless, culinary and laboratory agar are usually constituted of various kinds of seaweed. Agar in meals is normally extracted from Gracilaria, which grows readily in massive synthetic ponds and tanks.

Laboratory agar is a extra rarefied product. It comes from Gelidium, a slowly rising wild seaweed that yields a higher-quality agar whose decrease gelling temperature is extra appropriate for lab work. Lately, Gelidium is harvested primarily off the coast of Morocco, in keeping with Dennis Seisun and Nesha Zalesny, who run the industry-analysis agency IMR Worldwide. The purple, frilly seaweed could be collected when it washes ashore, however the finest-quality agar comes from Gelidium gathered from the seabed by skilled divers in the summertime. “If you happen to can reproduce the waters of Morocco in a pond, the corporate would do it,” Zalesny advised me, however Gelidium has to date resisted makes an attempt at mass cultivation.

The reliance on wild seaweed has prompted complications for labs earlier than. In 2015, a Gelidium scarcity prompted the wholesale value to almost triple. However scientists haven’t, up so far, been significantly eager to discover a substitute for his or her agar. Seisun and Zalesny used to work for an organization that makes gellan gum, an agar various that may be manufactured totally in a manufacturing facility—no divers wanted, no finicky wild seaweed. But the product by no means took off. “Agar nonetheless is the king and queen and the gold commonplace,” Seisun advised me. Protacio’s lab ended up switching to a unique agar provider—a less expensive one, really—and since then all the things has been simply superb.