Speed Virus Testing Has A New King: Nanobait
By Rishi Ganesh
Since the 1980’s, tests for viruses have been dominated by one form of testing. PCR testing, with its widespread availability, simple process, and relative speed to other tests. In the past, antigen tests designed for specific and niche types of virus were the most common form of tests. However, they often weren’t broad enough to test for a multitude of causes, resulting in a lot of cases where test results just came out too inefficiently for the population to be able to do anything about it. PCR is different, though – its methodology allows testers to isolate and identify pathogens using different, distinct genetic markers within the organism, making for a nearly universal test to identify microorganisms.
In my short time as a college student, I’ve been able to witness the efficiency of PCR tests firsthand through my experience in a research lab. Isolating the bacteria in the guts of honeybees, then plating them separately allowed me to create distinct colonies of bacteria. From there, using a “master mix” of reagents designed to foster rapid DNA replication, PCR (polymerase chain reaction) attempts to isolate a specific sequence of DNA that’s unique to every microorganism, yet is also universal. The gene, 16S rRNA, is a type of genetic material that makes up the ribosomes – the protein factories – of cells. This sequence of genes has existed for millions of years, and while its main structure stays the same, little differences in parts of the sequence are unique to each organism. Through PCR, we replicate this specific section of the RNA millions of times, allowing it to be identified through a simple comparison test. This process has been the most efficient way to test for pathogens for a few decades now, and it was essential to slowing the spread of the COVID-19 pandemic.
However, even PCR has its limitations. Only one type of pathogen can be tested for at a time, as it requires isolation to properly identify one organism. This process can take hours, despite it being potentially the fastest available test to the general population. Efficiency, especially in the world of infectious disease, can mean the difference between a breakout and a full-blown crisis. In order to be ready for the next pandemic, we have to improve on how fast we can respond.
To do this, scientists at Cambridge have begun to develop “nanobait” – a test that could be far more affordable and still more efficient than current-day PCR testing. Using open ends of DNA sequencing as bait, the test involves leaving these sequences through nanopores. The pathogens, which have RNA (a single-stranded form of genetic material, unlike double-stranded DNA), latch on to these open ends, where they can then be identified with extreme accuracy – closing in on an incredible 100%. Couple this with an extremely fast response rate – digital information can be analyzed in milliseconds – as well as affordability, and you get a test that is sure to have a prominent role in erasing pandemics before they begin.
