The scientific term "breakthrough" is often overused, but when it comes to the polymerase chain reaction (PCR), it truly deserves the label. Developed by the daring chemist Kary Mullis two decades ago, PCR allows biologists to replicate DNA – the building blocks of life – in a test tube. This groundbreaking technique won Mullis a Nobel Prize and transformed molecular biology. PCR makes it easier to identify, modify, and read DNA sequences, as it allows scientists to create billions of clones from a single molecule. It’s a game-changer for forensic science, as it can identify burglars and rapists, and even provide insight into people and animals who lived thousands of years ago.
Now, there’s a new technology on the block that could rival PCR’s dominance. Researchers at New England Biolabs in Massachusetts have developed a method for DNA amplification called helicase-dependent amplification that doesn’t require the use of a power-hungry machine. As the gene-editing revolution rolls on, this advancement could pave the way for cheaper and more robust gene replication.
The helicase-dependent amplification method works similarly to PCR but uses an enzyme called helicase instead of heat to break apart the two strands of DNA, which facilitates precise target sequencing. Speaking about the technology, Huimin Kong of New England Biolabs said, ‘We can do DNA amplification without instrumentation. We mix A with B, mix the blood sample with our reagent, and then, bingo, it’s done. We’re not trying to compete with PCR; we want to complement it in areas where it’s not easy for PCR to be adopted.’
Diagnosing diseases, particularly in developing nations, could be one area to benefit from this simpler and more accessible technique. By identifying specific target sequences such as those from the HIV virus, the technique could produce accurate and fast results, and distinguish between different strains of bacteria and viruses. Kong says that the team is working on creating a ‘real-time’ testing kit that could produce results in just 15 minutes, and at a low cost.
According to Boston University’s Natalia Broude, editor of the recently published book titled "DNA Amplification: Current Technologies and Applications," there is a rapidly increasing interest in potential substitutes for PCR. A host of contenders have surfaced, each utilizing a blend of innovative techniques like LCR (ligase chain reaction), CPR (cycling probe reaction), and RCA (rolling circle amplification). However, none of these alternatives has been able to establish themselves as a standout technology.
Broude comments, "PCR has been the majority market leader for over two decades; therefore, it has been widely researched. However, real-time approaches will soon gain traction and pose as a threatening competition as these approaches offer enhanced convenience."