A team from Nagoya University proposed a different tool—silver nanoparticles. They cause site-specific cleavage of chemically modified oligonucleotides. Under optimized conditions (with a polyethylene glycol coating, at 50 °C), cleavage efficiency exceeded 91% within 1–2 hours. By comparison, silver ions alone produced a yield of only about 14%.
The main advantage is the length of the sticky ends. The method makes it possible to obtain segments of 8 or even 18 bases. With eight-base ends, ligation proceeded about twice as efficiently as usual. With eighteen-base ends—almost fivefold (44% versus 8%). In addition, the nanoparticles retained unwanted cut-off fragments, so the pure product could be recovered with yields of up to 98%.
To verify functionality, the researchers assembled a fragment encoding green fluorescent protein (GFP) and introduced it into HeLa cells. The protein was expressed—meaning the assembly proceeded accurately and without critical errors.
For now, this is a laboratory protocol. But more reliable and faster assembly of long DNA constructs is needed for gene therapy, vaccine development, and plant engineering. Silver nanoparticles may become a convenient addition to the synthetic biology toolkit.
Author: Maksim Aleksandrovich Erdyakov