Faced with an ongoing lack of protective equipment and testing supplies, medical professionals have been seeking alternatives to accurately diagnose cases of COVID-19, a pandemic that has caused more than 11 million cases and more than 530,000 deaths worldwide. Supplies of nasopharyngeal swabs were some of the first testing materials to run low in mid-March, prompting a pivot to nasal swabs. More recently, saliva-based testing has come forward as an attractive, low-cost alternative.

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The first spit tests are already being sold to consumers, with more poised to apply for emergency use authorization from the US Food and Drug Administration soon. While saliva can be a crude sample for diagnosing disease using traditional PCR, it pairs well with a cheap PCR alternative known as loop-mediated isothermal amplification (LAMP), previously used to detect outbreaks of Zika and Ebola in resource-poor countries. Propelled by a global pandemic, researchers in the US and the UK are now modifying LAMP and assessing its utility as a diagnostic tool for COVID-19.

“By diversifying the possible choice of assay, you diversify the supply chain as well,” says Robert Meagher, a chemical engineer at the Sandia National Laboratory who develops tools for diagnosing emerging diseases. Making additional testing options available to healthcare workers will help mitigate backlogs if one reagent or material runs low.