New approach allows widespread adoption of the COVID-19 test for laboratory diagnostics

The portable test gives you the result in 36 minutes. Effective against dengue fever and other viruses

Clinical medical scientists at the Recontian Medical School (LKCMedicine) at Nanyang Technological University (NTU Singapore) in Singapore have demonstrated ways to improve the speed, processing time, and cost of the COVID-19 test.

The improved test method gives you results in 36 minutes. This is a quarter of the time required for the existing Gold Standard test.

Their new approach allows for wider adoption of the COVID-19 test for diagnostics in the academic or laboratory, especially for screening and research in countries and regions where laboratory capacity is limited. ..

Tests that can be run on portable devices can also be deployed to the community as screening tools.

Currently, the most sensitive method for testing COVID-19 is through a laboratory method called the polymerase chain reaction (PCR). This technique allows the SARS-CoV-2 virus to be detected by repeatedly copying and amplifying the viral genetic material.

A major bottleneck in testing samples is RNA purification-the separation of RNA from other components in patient samples-a laborious process that requires chemicals that are lacking worldwide. The procedure must be performed by highly trained technical staff and can take several hours.

Today, automated equipment for sample preparation costs hundreds of thousands of dollars and requires specialized laboratory facilities.

The method developed by NTU LCK Medicine combines many of these steps to allow direct testing of crude patient samples, reducing sample-to-result turnaround time and eliminating the need for RNA purification chemicals ..

Details of the new approach have been published in scientific journals gene In June.

Although the polymerase chain reaction (PCR) is a time-honored technique that has proven to be the mainstay of biological research, it has some drawbacks when used outside the laboratory environment. This process is tedious and time consuming. Our rapid testing of COVID-19 includes a single tube reaction that reduces the hands-on time and biosafety risks of lab personnel and the potential for carryover contamination during sample processing. .. “

Wee Soon Keong, PhD. , Study First Author, LCK Medicine, Nanyang Technological University

Apart from testing COVID-19, the same method developed by the NTU LCK Medicine team can also be used to detect viruses and bacteria in other countries. Outbreak of a coronavirus outbreak.

Associate Professor Eric Yap, who leads the research team, which is also headed by the Institute for Microbial Genomes, said: “We have previously demonstrated that this method is also effective against dengue virus. When used directly on crude blood samples containing dengue virus, this test yields 28 minutes.”

“Singapore is countering the double outbreak of dengue fever and COVID-19, both of which have similar initial symptoms, but our tests help distinguish between the two infections.”

Professor James Best, Dean of the NTU LCK Medicine, said: It is useful on community test sites so that you can quickly identify infected patients and take immediate steps to prevent infection. “

From benchtop to portable testing

Typically, PCR testing involves extracting the genetic material of a swab sample taken from a patient to remove any material in the sample for which the PCR test does not work. An example of an inhibitor in respiratory samples is mucin, the main component of mucus.

A test designed by the NTU LKC Medical Team includes a senior researcher at Dr. Shivalingham Paramarin Gum Sappia, which uses the “direct PCR” method to eliminate the need for RNA purification, a time-consuming and costly step. Eliminate

Instead, they added inhibitor-resistant enzymes and reagents that target compounds that inhibit RNA amplification, such as mucin, which is a major component of mucus.

These commercially available enzymes and reagents are highly resistant to compounds that would otherwise interfere with PCR, making testing inaccurate.

The crude sample and a biochemical mixture of inhibitor-resistant enzymes and reagents are placed in a single tube that is inserted into a laboratory thermocycler, a machine used to amplify genetic material in PCR. After 36 minutes, the results confidently reveal if there are any traces of COVID-19.

“By skipping the RNA extraction step in the direct PCR method, we can see the cost savings of nucleic acid extraction kits, avoiding the shortage of reagents as lab testing increases and global demand increases. Will be done,” said Dr. Shivalingham.

The team also tested the method on a portable thermocycler that could be deployed in low-resource environments or endemic areas, and noted the possibility of having this test performed by local healthcare professionals in the local healthcare setting.

Yap said: “We are currently trying to deploy such a direct PCR method developed by ourselves and others for routine diagnosis.”

“We need to determine the actual usability and benefits of the actual setup and understand if there are trade-offs. Once one bottleneck is removed, quality control, manual error reduction etc. , Other challenges may surface.”

The team is currently considering using this method for the COVID-19 test at the NTU Clinical Diagnostic Laboratory at LCK Medicine, headed by Professor Yap Assoc.

“Our goal is to develop ultra-fast automated tests that deliver results in minutes and allow clinicians to perform with the same accuracy and sensitivity as professional laboratories.”

“This will allow us to perform PCR tests in the most resource-demanding environment we need, closer to the point of care than traditional laboratories,” he said.