Chinese researchers develop fast, accurate, low-cost COVID-19 test

Beijing: Chinese researchers have developed a new low-cost diagnostic test for Covid-19 which quickly delivers accurate results without the need for sophisticated equipment.

"In this study, we developed an isothermal, CRISPR-based diagnostic for Covid-19 with near single-copy sensitivity," the study authors from Xuzhou Medical University in China, wrote in a paper published in the journal PLOS Pathogens.

"We demonstrated a CRISPR-based assay for Covid-19 that offered shorter turn-around time and great diagnostic value, even in under-resourced settings without the need for thermal cyclers," they added.

The surging demand for rapid screening and identification of Covid-19 poses great diagnostic challenges.

Metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) have been the most commonly used molecular methods for diagnosing Covid-19, but each has its own limitations.

For example, sequencing is costly and has a turnaround time of nearly one day, while RT-PCR requires specialized equipment and is difficult to deploy at a large scale.

According to the researchers, a lack of rapid and accurate molecular diagnostic tools has hampered efficient public health responses to the viral threat.

In the new study, the researchers developed an alternative Covid-19 test by leveraging CRISPR-based technology, which has been widely used in recent years for gene editing.

The assay, named CRISPR-COVID, enables high-throughput detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - the virus that causes Covid-19.

CRISPR-COVID delivers comparable sensitivity and specificity as mNGS within as short as 40 minutes, the researchers said.

When produced at a large scale, the material cost of a CRISPR-COVID test could be less than 70 cents, suggesting that CRISPR-COVID is a competitive alternative not only technologically but also financially, the team noted.