Home Health APL focused on rapid pathogen testing

APL focused on rapid pathogen testing

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Timely, accurate diagnosis is at the heart of an effective response to any emergent infectious threat. However, timeliness is a difficult bar to clear when testing requires that results be sent off to a lab for analysis. That issue is being addressed at the Johns Hopkins University Applied Physics Laboratory (APL), in Laurel.

Accuracy is often the first casualty of quick results, such as with antigen tests and rapid polymerase chain reaction (PCR) tests that are not performed by trained professionals. In an effort to change that, scientists at APL looked at the problem a different way.

The goal was to create a foolproof, accurate, on-the-spot test for detecting RNA viruses – one that could even be used at home. The method focused on not creating anything new, and instead using mature, off-the-shelf technology.

“This is a key problem; if you ask anyone who works in diagnostics, they will tell you they want a sensitive and portable product,” says Mekbib Astatke, a biochemist in APL’s Asymmetric Operations Sector. “You either have to invent a disruptive technology to address it, or you can take a couple of mature products and marry them to get there. My argument has always been that it’s better to get mature products and use a systems integration approach, and then you can potentially leapfrog the problem.”

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That is exactly what Astatke did. In collaboration with Olivia Tiburzi, a biotechnologist, and Amy Connolly, former APL scientist, the team combined two well-established technologies to prove the feasibility of a simple, quick, yet highly accurate test capable of detecting multiple known pathogens from a single liquid sample. The team’s work was recently published in the Journal of Immunoassay and Immunochemistry.

The first piece of the puzzle was nucleic acid sequence-based amplification (NASBA), a highly sensitive technique for detecting and amplifying RNA that has been around since the early 1990s; the second piece is lateral flow tests (LFTs), which capture target molecules in a substance and produce a visual signal indicating their presence or absence (similar to home pregnancy tests). Combined with the versatility and specificity of NASBA, the result could very well be a home test for a disease such as COVID-19 – not to mention Zika, Ebola or any other RNA virus.

“The advantage of targeting RNA is that even bacteria has RNA in multiple copies,” Astatke said. “Every living thing has RNA.”

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