New Microchip Real-Time Technology Platform for COVID-19 Testing Offers Alternative to Gold-Standard RT-QPCR Tests

The new microchip real-time technology platform uses 10-fold less reagents compared to Centers for Disease Control and Prevention (CDC)-approved tube-based RT-PCR tests, and reports results in as little as 30 minutes. Its accuracy was 100% predictive in clinical samples, according to the investigators.

The researchers validated a microchip PCR technology for detection of SARS-CoV-2 in clinical samples. Empty microchips with 30 microwells were manufactured from aluminum sheets and coated with surface modifiers. They were then filled with CDC-authorized primers and probes to detect SARS-CoV-2. They were individually packaged and sent to a laboratory for sample validation and testing. Real-time qPCR was performed using 1.2 micro liter reaction volume per reaction on a microchip-based PCR analyzer using AriaDNA software to control the instrument and obtain PCR results.

Nasopharyngeal swabs from eight patients with positive COVID-19 test results and 13 patients with negative COVID-19 test results were collected and tested with the microchip RT-qPCR kit. Of the 21 patient samples, eight tested positive, 12 tested negative, and one included sample was invalid, which tested negative in both the microchip RT-qPCR assay and hospital testing. The CDC standards deemed the sample invalid as the human internal control was not detected in this sample. The microchip kit miniaturized the reaction volumes needed by 10-fold, resulting in lower reagent consumption and faster assay times (in as little as 30 minutes compared to about 70 minutes), while maintaining the same gold standard in sensitivity as higher volume techniques. Because the kit comes preloaded with SARS-CoV-2 primers and probes, it may further reduce operator-associated errors, improving the reliability of analysis in remote settings.

"Sensitivity is critical for early detection of COVID-19 infection where the viral load is minimal to prevent further spreading of the disease. During this pandemic, numerous testing assays have been developed, sacrificing sensitivity for speed and cost," explained lead investigator Peter J. Unrau, PhD, Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. "This research offers a cheaper, faster alternative to the most reliable and sensitive test currently used worldwide, without sacrificing sensitivity and reproducibility."

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Simon Fraser University