Exploring the Potential of Gene Synthesis

May 20, 2024

Gene synthesis has revolutionised fields like protein engineering, biotechnology, and synthetic biology. As synthesis technologies become more advanced and affordable, it will enable more rapid progress in drug development, industrial biotechnology, and many other areas. This article will share more about its process and applications.

What is Gene Synthesis?

Gene synthesis, also known as DNA synthesis or oligonucleotide synthesis, involves chemically synthesising short strands of DNA within a laboratory setting. These synthetic DNA strands are designed on a computer and assembled base by base. It allows scientists to create custom DNA sequences quickly and precisely.

Why is it Useful?

Gene synthesis has many applications in biotechnology and medicine. It can be used to create DNA libraries for antibody discovery, optimise gene sequences for protein expression, and assemble whole gene constructs. This is a much faster alternative to cloning and mutagenesis techniques. It gives scientists complete control over the DNA sequence, allowing them to fix mutations, codons, and sequences as needed.

How Does it Work?

Gene synthesis involves three basic steps: design, synthesis, and assembly. First, the DNA sequence is designed on a computer and optimised for synthesis. Then, short single-stranded DNA oligonucleotides are chemically synthesised base by base. These oligonucleotides, usually between 20 to 60 bases long, anneal together into longer strands. Repeating the synthesis and annealing steps produces an entire gene construct.

The Process of Gene Synthesis

Gene synthesis, also known as DNA synthesis, is the chemical synthesis of DNA strands. Scientists and researchers employ this potent tool to study the inner workings of genetics. The process involves building new DNA molecules from scratch in the lab.

Step 1: Design

First, design the DNA sequence you want to synthesise using gene synthesis software. You input the sequence of nucleotides (A, C, T and G) that make up the DNA strand you want to create. The software will check for any errors in the sequence and optimise it for synthesis.

Step 2: Synthesis

DNA synthesis machines are then used to physically construct your designed DNA sequence. These machines assemble nucleotides in the specified order, synthesising short single strands of DNA. Subsequently, these strands are assembled into longer double-stranded DNA molecules. Multiple synthesis cycles are typically necessary to construct an entire gene.

Step 3: Assembly and Cloning

Next, assemble the synthesised DNA strands in the correct order and orientation. Then, combine them to a vector using enzymes and clone them by inserting them into bacterial cells, which are grown in culture and reproduce, amplifying the amount of DNA.

Step 4: Sequencing and Delivery

Finally, the cloned DNA is sequenced to check that it matches the designed sequence. Once verified, the synthesised DNA, now called a gene construct, is ready to be delivered to researchers and scientists for their studies and experiments.

Gene synthesis has enabled huge advances in biotechnology and medicine. From modified crops to targeted cancer therapies, this process has opened up a whole new world of possibilities. 

PCR Cloning vs Gene Synthesis

Gene synthesis and PCR cloning are both common techniques used in molecular biology for manipulating and generating DNA sequences, but they serve different purposes and have distinct advantages.

PCR Cloning

PCR cloning involves amplifying a DNA sequence of interest using polymerase chain reaction (PCR) and then inserting the amplified fragment into a vector for further manipulation or expression. Here are some key points about PCR cloning:

  • Targeted Amplification: PCR cloning allows for the specific amplification of a DNA fragment of interest from a template DNA.
  • Versatility: It is suitable for cloning relatively short DNA sequences, typically ranging from a few hundred base pairs to several kilobases.
  • Site-Directed Mutagenesis: PCR cloning can also be used for introducing site-directed mutations into a DNA sequence.
  • Cost-Effective: PCR cloning is generally more cost-effective than gene synthesis for short DNA fragments.

Gene Synthesis

Gene synthesis involves chemically synthesising a DNA sequence de novo, without the need for a template DNA. Here are some of its key points:

  • De Novo Synthesis: Gene synthesis allows for the creation of custom-designed DNA sequences, including entire genes or gene constructs.
  • Length and Complexity: It can synthesise longer DNA sequences, ranging from hundreds to thousands of base pairs, making it suitable for synthesising entire genes or complex genetic constructs.
  • Sequence/Codon Optimisation: Gene synthesis enables the optimisation of DNA sequences for codon usage, gene expression, and other parameters.
  • Complex Manipulations: It facilitates the introduction of specific modifications, such as point mutations, insertions, deletions, or gene fusions, with precision.
  • Higher Cost: Gene synthesis is typically more expensive than PCR cloning, especially for longer DNA sequences.

Choosing Between PCR Cloning and Gene Synthesis

The choice between PCR cloning and gene synthesis depends on factors such as the length and complexity of the DNA sequence, the need for sequence optimisation or specific modifications, and the available budget. PCR cloning suits cloning short DNA fragments and targeted mutagenesis, while the latter is preferable for synthesising longer or custom-designed DNA sequences and complex genetic constructs. In many cases, researchers may use a combination of both techniques to achieve their experimental goals efficiently.

Applications of Gene Synthesis

Gene synthesis has enabled scientists to create custom DNA sequences for a variety of useful applications. One of the biggest benefits is that it allows researchers to study specific genes and better understand their function. Scientists can order synthetic genes to insert into organisms like bacteria, yeast, and mammalian cells to see how they work within a living system.

Functional Genomic Libraries

Researchers employ synthetic genes to create comprehensive libraries for functional genomics studies, including CRISPR screens, RNA interference (RNAi) assays, and protein-protein interaction studies. Functional genomic libraries play a pivotal role in deciphering the functions of genes and understanding their roles in various biological processes

Vaccine Development

In vaccine development, researchers employ gene synthesis to produce recombinant antigens for immunisation studies. They synthesise and express synthetic genes encoding antigenic proteins from pathogens in host organisms or cell culture systems to generate vaccines against infectious diseases.

Metabolic Engineering

In metabolic engineering, gene synthesis enables the construction of synthetic metabolic pathways for the production of biofuels, pharmaceuticals, and other valuable compounds. Custom-designed gene sequences encoding enzymes involved in metabolic pathways can be synthesised and engineered into microbial hosts for the production of desired metabolites.

Gene Synthesis Services at Bio Basic 

Bio Basic Asia Pacific offers in-house plasmid vectors and accepts custom vectors from your team for synthesis. Our comprehensive service includes complimentary codon optimisation and cloning into default vectors. Once the sequencing is complete, we will provide the following deliverables:

  • 2 – 4 μg of lyophilised plasmid DNA
  • ABI file for DNA sequencing
  • SQD file for Sequence Alignment
  • A gene synthesis report
  • Gene sequence in SEQ format

To find out more about the information needed to place an order, check out our standard gene synthesis service page.