News from across RSC Publishing.
Miniaturised sewing machines
23 June 2008
Single threads of DNA can now be manipulated using miniaturised hooks and bobbins, thanks to Japanese scientists.
Taking their inspiration from sewing, Kyohei Terao from Kyoto University and colleagues designed these laser-directed microdevices to pick up and manoeuvre giant individual molecules of DNA.
Using miniaturised hooks and bobbins single DNA strands can be manoeuvred without breakage
Single molecule analysis of DNA is limited by the difficulty of stretching out and handling these long molecules - eukaryotic DNA can range from millimetres to centimetres. A giant DNA molecule is very fragile, explains Terao, so to catch it and manipulate it without breaking it is a challenge.
Thinking of a strand of DNA as a piece of sewing thread, Terao developed microhooks to pick up the DNA, just like we would use our fingers to pick up thread. When thread is very long it becomes tiresome to manipulate it just with our fingers and instead we wind it around bobbins to make it compact. This is what inspired us to use microbobbins, says Terao.
This DNA manipulation technique should prove useful in applications such as fluorescence in situ hybridisation (FISH), says Terao. FISH is used to locate a gene on a DNA molecule using fluorescent gene markers, providing useful information for the diagnosis of genetic diseases and analysis of chromosome function. However, DNA has randomly-coiled conformations, which can hamper observations. But when a DNA molecule is manipulated and straightened by microhooks and bobbins, the gene location can be determined easily with high-spatial resolution, says Terao.
It is 'an excellent idea to fabricate unique microtools that enables us to manipulate a single giant DNA molecule', says Yoshinobu Baba, who researches biologically useful microdevices at Nagoya University, Japan. The technology will also be useful for a number of other applications including DNA sequencing and molecular electronics, he adds.
Link to journal article
On-site manipulation of single chromosomal DNA molecules by using optically driven microstructures
Kyohei Terao, Masao Washizu and Hidehiro Oana, Lab Chip, 2008, 8, 1280
Also of interest
Chemically-powered molecular scissors and tweezer-like triangles offer new ways to manipulate structures on the nanoscale
US scientists have set DNA detection in a spin by exploiting one of nature's molecular motors.
Yoshinobu Baba tells Celia Clarke how nanotechnology could measure our health and happiness.