Editor’s Note: This article was originally published by University of Washington Medicine on September 23, 2020, featuring Drs. James Chen, Thomas Lendvay, and Tanner Clark, Singletto founders.

Original Link

Since April, investigators have studied how to disinfect coronavirus-exposed N95 masks so healthcare workers can reuse them safely.

The shortage of personal protective equipment (PPE), specifically N95 masks, remains an issue globally. With the fall flu season compounding the current coronavirus pandemic, U.S. hospitals' supply will be further strained.  A UW Medicine urologist and a radiology fellow are looking for a work-around.

For the last six months, Drs. Thomas Lendvay and Tanner Clark have worked with Dr. James Chen, a Seattle neurosurgeon, examining the viability of disinfecting N95 masks so healthcare workers can reuse them safely. Infectious diseases specialist Jaya Sahni of Seattle Children’s Research Institute also became a collaborator after his lab pivoted from studying HIV to COVID-19 after the pandemic emerged this spring.

Industry-standard masks, including the N95, are designed as single-use devices. It is very difficult to sanitize them without destroying them or rendering them toxic to the wearer. Currently a few commercially available products and methods effectively disinfect PPE, but most require expensive equipment that many hospitals cannot afford or manage.

Lendvay, a professor in the urology department, University of Washington School of Medicine, is studying whether methylene blue, combined with light, could disinfect PPE quickly, inexpensively, and without causing PPE to become ineffective or unsafe. Methylene blue is a readily available chemical, even in developing countries. It is used in the sterilization of blood plasma for transfusion and is also a topical method of sanitization once it encounters light or sunlight.

If this solution is viable, it would significantly increase the volume of available protective gear worldwide. Lendvay started this work with a $100,000 Amazon grant and funding from an anonymous donor in Seattle.

His investigation is now part of the DeMaND study (Development of Methods for Mask and N95 Decontamination), which involves researchers from the Centers for Disease Control and Prevention, the World Health Organization, and from 12 institutions including the University of Washington School of Medicine.

“We are testing whether methylene blue plus bright light can kill virus on N95 masks and PPE so that we can provide healthcare workers with a better and safer solution for reusing their gear,” said Lendvay. “Because methylene blue and light are widely available and inexpensive, we believe that this solution can scale to nations around the globe with fewer resources and where support for healthcare workers is scarce.”

Results from Lendvay’s work and that of the other universities are expected to be published this fall.


November 15, 2021
Protective Dye Methylene Blue Plus Light Proven to Inactivate "Hard-to-kill" Norovirus

Singletto's Dr. Lendvay contributed to a New MB Study


May 22, 2021
Infection Control & Hospital Epidemiology Publishes Drs. Lendvay, Chen, et al. WHO-led DeMaND Study

The Infection Control & Hospital Epidemiology medical journal has published the peer-reviewed DeMaND study. Singletto’s Dr. Tom Lendvay served as Lead Author.


May 20, 2021
Top Doctor 2021: Singletto’s Lendvay Named by Seattle Magazine

Dr. Thomas Lendvay, Singletto’s Co-Founder and Chief Medical Officer was just named a “Top Doctor” by Seattle Magazine.


March 25, 2021
A Moral Obligation: Why the Former Providence President Wants Singletto Tech Out Now

Mike Butler spent over two decades in leadership at Providence Health, growing such from a $2 billion organization to $25 billion. Upon recently retiring, Mike knew he wanted to find ways to continue impacting the lives and health of others. Now at Singletto, Mike is on a mission to bring the novel Singletto technology to market – in healthcare and beyond. But, it’s not just a passion project … upon learning about the technology, Mike felt a moral obligation to get it in as many hands as possible. More with recently retired Providence Health President Mike Butler…


February 25, 2021
Hospital News: Light kills. SARS-CoV-2, That Is.

Singletto Advisor Dr. Belinda Heyne shares DeMaND study results on Hospital News.

Lacey Duffy

Customer Experience
February 12, 2021
CBC: This simple mix of dye and light could decontaminate masks for reuse

Dr. Belinda Heyne was recently featured in a CBC piece covering the DeMaND study’s findings and the life-giving potential of dye and light.