S.F. startup Phylagen’s quest: airborne COVID-19 detection in offices

April 18, 2022 /Roiland Li, The San Francisco Chronicle/ – When the COVID-19 pandemic turned the world upside down in 2020, Jessica Green’s interest in safe buildings went from a corporate afterthought to global priority.

“That trigger was an awakening in the world where, now, almost everybody understands that we live submerged in this ocean of air indoors — we spend 90% of our lives indoors — and we’re surrounded by this very rich microbial ecosystem,” Green said. “The majority of the spaces that we work, live and play in are managed in a very unintentional way with regards to indoor air quality, and it doesn’t have to be that way.”

Green, CEO of San Francisco startup Phylagen, is on a quest to develop an airborne monitoring system that will alert businesses of the presence of coronavirus particles, other viruses and even allergens like pollen. The company hopes to release a prototype within a year.

Currently, the company trains on-site workers such as janitors to collect samples from offices twice a week with hand swabs. Those are shipped to one of three Phylagen labs, including one at its South of Market headquarters, and sequenced through PCR tests, with results available in a few hours.

Phylagen’s major client is Silverstein Properties, owner of multiple World Trade Center towers in New York, where tenants include tech firms Uber and Spotify. Green said Phylagen is also working with a global tech firm based in Silicon Valley, which she wouldn’t identify.

Green sees the technology as a way for companies to bring back workers safely and a way to detect the presence of the coronavirus even if employees aren’t showing symptoms. Long term, it’s a way to manage offices and ensure optimal air quality. Phylagen also develops software for clients that show floor-by-floor test results through an online dashboard.

The goal of an automated airborne detection system is to remove the manual labor component of swabbing and increase the frequency of data collection. Challenges for airborne detection include collecting enough sample material, which is more dispersed in the air compared to surfaces.

“It’s, in the long-term, going to be much more seamless to have sensors that are no-touch, collecting data and pushing that data to the building automation system,” Green said.

Green, a Bay Area native, received her doctorate in nuclear engineering at UC Berkeley. A mentor encouraged her to look into microbial ecology, and in 2000 she read a paper about how collecting an environmental sample and analyzing DNA sequences could reveal what tiny organisms were present.

After stints in academia at the University of Oregon and UC Merced, Green co-founded Phylagen in 2015 with the goal of reading microbial data in buildings as a way to manage air quality.

Before the pandemic, the company worked to trace microbial material in supply chains to ensure shipments weren’t contaminated. After coronavirus arrived, Phylagen first deployed environmental testing for logistics customers in warehouses, before shifting fully to focus on office buildings. Since the samples are collected from the environment, Phylagen isn’t subject to government testing regulations and can ship them over international borders.

The company has raised $14 million from investors, including from the industrial giant 3M, maker of N95 masks, and Peter Thiel-backed Breakout Ventures. (The company name is derived from phylogeny, or the study of how parts of organisms evolve.)

Green declined to disclose how many customers the company has, but said the testing has encompassed over 100 million square feet and 18 cities. Revenue has increased by 10 times in the past year, Green said, but wouldn’t give specifics. Employee count risen 40% to around 40 people.

Phylagen isn’t alone, and some companies already sell airborne detection products. Another Bay Area startup, Poppy, developed a device that’s been compared to a COVID “smoke detector.” New Mexico startup BioFlyte has an airborne detection system called the Sentinel.

“It is promising from my point of view that we are seeing competitors emerge in the market. And it’s just an indication that there is real market demand and public understanding of the need to put biology in the mix in terms of providing healthy indoor environments,” Green said.

The current swabbing system is a cheaper alternative to human testing and less intrusive, while being more focused than another prominent practice, wastewater testing. Taking samples from a zone of desks and getting a positive test can narrow it down to a dozen people, while wastewater testing could encapsulate thousands of people.

Dave Coil, a project scientist at the UC Davis Genome Center, worked on a pilot effort to swab air filters at local elementary schools to collect samples. The technology was similar to Phylagen.

“Everything has its pros and cons. Swabs are much more labor intensive,” but it yields more targeted data about where the virus is, Coil said. An airborne detection system wouldn’t require as much labor but might not specifically pin down what area of a building has the virus. Another challenge for swabbing is timing: A positive result doesn’t reveal when the virus was shed, so more frequent sampling is better. An airborne system that’s always on would have an advantage.

Another hurdle is whether PCR tests could be done on-site rather than in a lab as part of a detection system, which would significantly cut down on the time it takes to get results by removing shipping times.

The technology is possible said Coil, whose manager, Jonathan Eisen, is on Phylagen’s science advisory board. Coil has also discussed testing methodology with the company.

“Wastewater (testing) is here to stay. It’s proven itself beyond a doubt,” Coil said. “Indoor sampling is more experimental, in my opinion.”

Another risk for Phylagen and other startups in the field is that as the pandemic wanes, environmental testing will no longer be a priority for companies, but Green believes the world’s mindset has changed permanently.

“I don’t think the world is ever going to be going back on multiple levels,” Green said. “Scientists don’t believe that COVID is going away anytime soon, it may become something that looks more like the flu. But we know that even the flu alone is a tremendous financial burden on companies.”