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Viral Ecology Research Hit by Filter Shortage

Researchers studying viruses in the environment are scrambling to stockpile tiny laboratory filters called Anodiscs after GE Healthcare announced it would stop making them at the end of the year.

Down to their last filters and with boxes on back-order, many labs have stopped ongoing research projects. Environmental microbiologist Jed Fuhrman of the University of Southern California in Los Angeles calls the situation a "nightmare" adding that his lab paused a 10-year project of collecting monthly virus samples from the waters between Los Angeles and nearby Catalina Island. The filter shortage "pretty much killed that project," Fuhrman says.

Why do these filters matter so much? To study viral diversity in the ocean or within soil samples, environmental microbiologists must count how many viruses they find. The easiest, cheapest way to count viruses has been to filter samples through Anodiscs, stain the viruses with a fluorescent dye, and then count the glowing dots on a microscope. Unlike filters made by other companies, these quarter-sized filters don't glow themselves, which allows scientists to pick out the faint virus spots from a dark background. "It's a little bit of a house of cards, because these techniques are all built on one filter made by one manufacturer," says environmental microbiologist Eric Wommack of the University of Delaware in Newark. An alternative counting method called flow cytometry requires more expensive equipment and greater expertise to get reliable data.

GE Healthcare acquired Whatman, the company that previously made Anodiscs, in 2008 and plans to discontinue the product on 31 December. In an e-mail to ScienceInsider, a company spokesman wrote that GE Healthcare is looking for "potential solutions," but wouldn't disclose what they were.

Wommack and other researchers are writing a letter to GE Healthcare explaining the importance of the Anodiscs to their field. Through former National Science Foundation director and environmental microbiologist Rita Colwell, the scientists have found about a dozen National Academies of Science members to co-sign the letter. "We want to make sure the company understands that a lot of work has been done with their filters and that this is a serious matter," Colwell says.