Problems and solutions constantly appear before us as do islands form in the blues of
the ocean. As our world moves forward, debates and conflicts often arise, but so do
resolutions and settlements: an island for an island. While pondering about an issue, one can
often imagine what needs to be done in the future to solve it, gazing over at the solution from
afar, and realizing that the solution is very much in sight and just an island away. Still, there’s
a wide ocean that barricades us from bursting forward to grasp the torch of enlightenment -
and it’s our job to find our ride across.

“The Double Helix” has sold over a million copies since its publication in 1968
(Wade, 2003). Since molecular biologists James Watson and Francis Crick uncovered the
secrets to DNA’s appearance, the scientific world has been on an obsessive rampage for
discovery. With new concepts to visualize, and more classified data to analyze, it provides a
formidable amount of room for innovation, and a new ‘sea’ for pioneering. However, the
microscopic size of our DNA molecules poses a colossal challenge for any type of
manipulation or testing. Naturally, scientists realized we needed a way to synthesize more
copies of DNA to facilitate experimentation effectively. As such, two islands had emerged in
the sea of genetic innovation.

On a moonlit April night in the Bay Area, in 1983, Kary Mullis encountered an
identical proposition while driving home to his weekend cabin after packing up work at the
biotech company Cetus Corporation. He was rethinking the minor logistics for a
DNA-sequencing experiment in his head when in a moment of sublimity, his jumbled
thoughts seemed to align with one another, and the individual fragments of the process
known to us all as Polymerase Chain Reaction (PCR) started to piece together (Kagan, 2021).

In Mullis’s mind, the raw concept of PCR comprised denaturing the DNA at high
temperatures to form single strands and allowing the appropriate primers to bind to its ends.
This would give way for the enzyme DNA Polymerase to complete the process of DNA
replication, which resulted in the formation of two identical molecules of the original genetic
material. Then, “the whole cycle could be repeated, there being added every time a fresh dose
of the enzyme”, as they too, denature once the temperature is raised (Kaunitz, 2015). On the
surface, the process appears to function well. However, once one recognizes the tedious
amount of time genetic engineering takes in general, whether it be gene isolation or
centrifugation, “resetting the PCR reaction as many as 40 times over a 4-5 hour period”
seems exorbitantly impractical (Scientific, 2023). That’s where our lifeline, Taq Polymerase,
comes into play.

While conducting research in the wilds of Yellowstone National Park in the 1960s,
microbiologist Thomas Brock discovered a species of bacterium, Thermus aquaticus (T.
aquaticus), lurking in the superheated environs of the park’s thermal springs (Kagan, 2021).
Because the extremophilic bacteria endure such harsh temperatures, the biological

macromolecules and enzymes inside the bacteria have become accustomed to high
temperatures, including its DNA Polymerase, which we call ‘Taq Polymerase’.

Incorporating Taq Polymerase into Mullis’s original model of PCR meant that
molecular biologists now had a thermostable enzyme capable of repeat PCR cycling without
adding fresh DNA Polymerase after each cycle. Identifying this molecule not only saved
millions of scientists countless hours of idle waiting but also gave them time and opportunity,
encouraging them to develop gene technology further to a whole new level - it was enough
for the AAAS (American Association for the Advancement of Science) to name Taq
Polymerase as 1989’s Molecule of the Year in its academic journal, Science (Guyer, 1989).

All in all, the story of Taq Polymerase’s discovery allows us to appreciate how much
the science of molecular biology depends on its capabilities. Whether it be gene sequencing,
cloning, paternity testing, or forensics, all of these jobs and luxuries that we have in today’s
world would not exist had Taq Polymerase not been found. And even just recently, with the
onset of the COVID-19 pandemic, real-time PCR was used extensively all over the world to
detect and diagnose patients infected with COVID-19, which required the services of Taq
Polymerase. It may be just a sequence of microscopic amino acids bound together, but it’s our
ride across the sea of gene technology, destined for greatness.

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By Bhuminan (Toya) Chotichaicharin