![]() An optical fiber carried the laser light through the opening beneath a door and into the chamber that housed the samples of SARS-CoV-2. The laser was positioned in a hallway outside the laboratory. "We were trying to get a clear message of how much light we need to inactivate just the SARS-CoV-2 virus."Īn overview of the researchers’ setup. "What NBACC was able to do was grow the virus, concentrate it, and remove everything else," Miller said. Recently, use of nontoxic LED lamps as a UV light source has mitigated some of these concerns.įor this study, the NIST collaborators worked with biologists at NBACC, whose research informs biodefense planning on biological threats such as anthrax and Ebola virus. One reason is that traditional sources of UV light sometimes contain toxic materials such as mercury. Other wavelengths can break down proteins, destroying the virus itself.Įven though people have known about UV light's disinfection abilities for more than a hundred years, there's been an explosion in UV disinfection research in the past decade. Some wavelengths can damage microbes' RNA or DNA, causing them to lose the ability to replicate. This project built upon earlier work the NIST team did with another collaborator on inactivating microorganisms in water.ĭepending on the wavelength, UV light damages pathogens in different ways. "Long-term, hopefully this study will lead to standards and other methodologies for measuring UV dose required to inactivate SARS-CoV-2 and other harmful viruses." "Right now, there's a big push to get UVC disinfection into the commercial atmosphere," said NIST researcher Cameron Miller. Manufacturers of UV disinfection devices and regulators can use these results to help inform how long surfaces in medical settings, airplanes, or even liquids should be irradiated to achieve inactivation of the SARS-CoV-2 virus. "When you have material like the simulated saliva around the virus, that can reduce the efficacy of UV decontamination approaches." "I think one of the big contributions of this study is that we were able to show that the kind of idealized results we see in most studies don't always predict what happens when there's a more realistic scenario at play," said Michael Schuit of NBACC. This may make the findings more directly informative than those of previous studies. ![]() Suspending the virus in simulated saliva creates a situation similar to real-world scenarios involving sneezes and coughs. In the study, it took a smaller UV dose to inactivate viruses when they were placed in pure water than when they were placed in simulated saliva, which contains salts, proteins and other substances found in actual human saliva. Researchers also showed that the virus's surroundings can have a protective effect on the virus. UVC light (full range from 200 to 280 nm) is shorter than the UVB wavelengths (280 to 315 nm) that cause sunburn. The most effective wavelengths were ones in the "UVC" range between 222 and 280 nanometers (nm). So, what is SARS-CoV-2's kryptonite? As it turns out, nothing special: The virus is susceptible to the same wavelengths of UV light as other viruses such as those that cause the flu. Their experiment tested more wavelengths of UV and visible light than any other study with the virus that causes COVID-19 to date. Classified as Biosafety Level 3 (BSL-3), the lab is designed for studying microbes that are potentially lethal when inhaled. In a new paper published this week in Applied Optics, the collaborators describe their novel system for projecting a single wavelength of light at a time onto a sample of COVID-19 virus in a secure laboratory. Department of Homeland Security Science and Technology Directorate laboratory, overcame both these obstacles and completed what may be the most thorough test ever conducted of how several different UV and visible wavelengths affect SARS-CoV-2. Second, they need to illuminate the virus with a single wavelength of UV light at a time, with minimal changes to the experimental setup between tests.Ī recent collaboration between the National Institute of Standards and Technology (NIST) and the National Biodefense Analysis and Countermeasures Center (NBACC), a U.S. First, they need to separate the virus completely from extraneous substances in the environment. Answering those questions requires scientists to overcome two main obstacles.
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