What is Microfluidics PCR Testing

A male scientist doing experiments in a test tube.

Since the start of the coronavirus pandemic, scientists have been working tirelessly to develop the technology used in COVID-19 testing in order to deliver the most accurate results in the quickest time possible, all at an affordable price.

The methods developed early on have served populations well. However, newer and more advanced approaches are now beginning to outpace some of the cheaper ones that have been used worldwide since the start of the pandemic.

Here at AllClear, we’re constantly looking out for new FDA/ EUA approved technologies we can use to offer our clients the best testing services around.

Thanks to our partner test manufacturers, we are one of the few testing providers pioneering game-changing microfluidics technology that sets us apart from the rest. Keep reading to find out why.

What is Microfluidics?

First up, let’s break down the definition of what microfluidics actually are. When it comes to COVID-19 testing, microfluidics technology works using cartridge-based tests that split samples up into a series of very thin channels.

At the end of these channels, there are various different detection chambers that work to provide a result. These cartridges are processed inside a cycler machine.

Within the AllClear team, we like to think of microfluidics technology as the equivalent of a miniature, automated lab. This is because it operates in a sequential, step-wise manner which is comparable with that of any lab-based test.

What Else is Microfluidics Used For?

Microfluidics technology has been used since the 1980s for drug testing.

It’s particularly useful because it enables technicians to test for the presence of various different substances at the same time. This works because each channel within the cartridge is equipped differently to test for a particular substance.

How is it Used in PCR Testing?

Let’s start off by explaining how microfluidics technology is used in PCR testing.

A microfluidics PCR test comes in the form of a cartridge that branches off into channels inside. The COVID sample sits in a vial on top of these channels, and a magnetic bead system extracts the virus from the rest of the sample.

In the case of our rapid PCR saliva-based test, the saliva mixes with small magnetic particles which are coated with specific antibodies. These connect to the viruses in the sample and extract them.

As the sample travels further down the channel, the magnetic beads separate from the sample, leaving it in its purer version. This version is then heated and exposed to enzymes that separate the proteins and virus into its components, including the RNA that is going to be analyzed for.

Next, the sample is channeled into canals within the cartridge, which are then heated and cooled repeatedly, just like they would be in a lab.

Once triggered by heat, a series of plungers and chambers in the cartridge open up, mix with the reagents, and fluorescent antibodies are added. Once the sample reacts with the antibodies, this gives off a signal that the machine reads to provide either a positive or negative COVID result.

This type of PCR testing is expected to be approved by the FDA in the coming weeks. AllClear is part of the manufacturer’s “early adopter” program providing swift access once approved.

What is Microfluidics in Antigen Testing?

When it comes to antigen testing, microfluidics technology works in a similar way.

The COVID sample — obtained through a nasal swab — is then transferred to a test cartridge. Once inserted into the cycler machine, the sample is put through a series of steps, including heating, to purify and extract the antigen of the virus (if it’s present).

The antigen is then directed through the thin channels in the cartridge. In the last chamber, it reacts with a detection system, which then gives off a signal and turns into a result.

Why is it ‘game-changing’?

The lateral flow antigen tests that currently exist on the market are simple, not too technology-heavy, and cheap to run. This simple process means these tests require a fairly high amount of antigens in order to give a positive result. As a consequence, they often produce a high rate of false negative results.

Microfluidics technology, however, can offer lab-equivalent accuracy in a faster turnaround time, and produce a lower rate of false negatives.

For clients attending one-off events, the almost immediate result that this form of testing provides can give them the peace of mind that they can safely participate in the event for 12 to 24 hours.

This technology also requires minimal human interaction in comparison with lab-based testing. It uses small, cycler machines that are about the size of a toaster. They are extremely safe to use and carry a very low risk of contagion for our testing technicians.

Unlike those who work in a lab, AllClear’s technicians are not dealing with fluids or pipetting liquids from one vial into the next. All they do is take the sample, put it into the cartridge, insert it into the machine, push a button, and the work is done for them. Despite this, our technicians still wear PPE in compliance with COVID regulations.

How Sensitive Is Our Technology?

We define sensitivity as the ability to pick up evidence of an existing COVID-19 infection if there is one. Any infection these tests don’t detect is defined as a “false negative,” which could potentially spread if it goes undetected.

Cheap lateral flow rapid antigen tests are approximately 80% sensitive in people who show symptoms of the coronavirus. In the asymptomatic population, however, the sensitivity rating of these tests reduces to between approximately 55-60%.

What does this mean? A whole lot of false negatives.

Lab-based tests, on the other hand, can be anywhere between 90-98% sensitive.

Here at AllClear, our technology offers a sensitivity rating north of 95% for PCR tests, and around 97% sensitivity for antigen tests. This way, we can strive for a low rate of false negatives and limit the number of people who slip through the cracks.

Looking to the Future

AllClear is constantly looking out for new, efficient COVID testing technology to ensure we bring our clients the best in class. One of the avenues we are interested in exploring in the future is neutralizing antibody testing, which our partners are currently working on developing.

Furthermore, as COVID-19 mutates, the emergence of new variants has prompted a flurry of testing providers to develop new technology to detect them. When it comes to PCR microfluidics testing, the instruments we leverage have reserved one empty channel in the cartridge to add reagents to and test for the different COVID variants that are emerging.