Japanese scientists use tiny silver particles to make DNA assembly up to 5x more efficient
Summarized from sciencedaily.com
Japanese scientists have developed a method using silver nanoparticles to significantly enhance the efficiency of DNA assembly, achieving efficiencies up to five times greater than those obtained with conventional restriction enzyme methods. This technique involves cutting and reconnecting short pieces of DNA at targeted sites more effectively than traditional approaches.
The researchers replaced silver ions used in previous reactions for cutting 3’-thiol-modified DNA with silver nanoparticles. By coating these nanoparticles with polyethylene glycol (PEG), they improved the stability and dispersion of the particles, allowing for higher efficiency in DNA cleavage without damaging long DNA molecules. This method resulted in a DNA cleavage efficiency of nearly 100% at 95°C within two hours, which was later optimized to achieve efficiencies above 91% under ambient temperatures within one to two hours.
The use of silver nanoparticles also provided a built-in purification effect by keeping unwanted DNA fragments attached to the nanoparticle surfaces while allowing desired fragments with sticky ends to remain in solution. This led to an increase in final DNA recovery rates from 14% to 98%. Additionally, this technique enabled the production of DNA fragments with longer overhangs, such as 8-base and 18-base sticky ends, which are challenging to generate using conventional methods. When T4 DNA ligase was used to connect these fragments, joining efficiency was notably higher compared to traditional approaches.
The practical application of this method is demonstrated by its successful use in assembling a DNA fragment encoding green fluorescent protein (GFP) within human HeLa cells, confirming the accurate assembly and expression of the gene. The researchers suggest potential uses for this technology in synthesizing genomic DNA for applications such as mRNA library establishment for cancer vaccines, gene therapy, development of artificial protein drugs, and genome crops. Further research is planned to explore the possibility of joining multiple DNA fragments simultaneously, which would be crucial for building comprehensive genome-scale DNA constructs.