Have you ever stopped to think how far the field of genetic engineering has progressed in the last few decades? It’s simply astonishing. Thanks to the rapid development of gene synthesis and assembly technology since the 1960s, our capability to synthesize genes has skyrocketed from less than 100 bp to more than 1,000,000 bp. With such powerful advancements at our fingertips, we’re able to make unimaginable progress in metabolic engineering, genetic network design, and vaccine development.
Gene synthesis methods are not interchangeable, and each has its own niche depending on the requirements of the project. Here’s an overview of the most common gene synthesis methods:
Solid-phase synthesis: This is the traditional oligonucleotide synthesis methods that use a small volume of solution processed in a column full of chemicals. The oligonucleotides are synthesized by attaching nucleotide residues stepwise to the end of the chain, one-by-one. The integrity of the sequence and the productivity of the synthesis are hindered for products longer than 200 bp, and thus this method is generally limited by DNA sequence length. However, it compensates with its high accuracy.
Chip-based DNA synthesis: In this method, microarray chips utilizing electrochemical techniques are used to synthesize different kinds of oligonucleotides in different specific parts of the chips. Gene fragments in subpools are assembled and amplified to build the target gene. While cheaper and yielding larger amounts of the target gene than solid-phase synthesis, the accuracy of the synthesis is compromised.
PCR-based enzyme synthesis: This method uses a variety of cell systems to generate gene fragments. Different incision enzymes and label markers are used to add different kinds of genes to chromosomes, with no limits to the length of the target gene. This method performs well in synthesizing large gene fragments with high accuracy.
With the help of these gene synthesis methods, scientists can modify and design genes. Scientists have already synthesized and assembled a gene fragment of over 100 kbp, which, when inserted into a host bacterium lacking its genetic material, successfully produces new cells. Gene synthesis methods can even be used to construct new metabolic systems in living cells. A prime example is Jay D. Keasling’s construct to produce artemisinin, an important component in some anti-malarial drugs. Keasling’s system in E. coli and S. cerevisiae reduced the cost of artemisinin production by tenfold, showing that gene synthesis has tremendous potential in medicine and countless other fields.
In summary, gene synthesis methods have revolutionized the field of genetic engineering, providing us with powerful tools to rebuild and expand genetic material. Although there are a few drawbacks to each method, scientists are vigorously improving them day by day, giving us the potential to derive unimaginable benefits from this technology. From metabolic engineering to vaccine design, gene synthesis methods have been instrumental in unlocking some of the most astonishing achievements in modern science. We’re only scratching the surface of what can be accomplished with this technology, and the future looks brighter than ever.