DNA sequencing to get quicker and cheaper!

LONDON - DNA sequencing is set to become cheaper as scientists have made a new technique that would allow rapid, low cost reading of whole genomes, through recognition of the basic chemical units-the nucleotide bases that make up the DNA double helix.

Stuart Lindsay, of the Biodesign Institute at Arizona State University, said that his technique for reading the DNA code relies on a fundamental property of matter known as quantum tunnelling, which operates at the subatomic scale, reports Nature.

According to quantum theory, an electron has some probability of moving from one side of a barrier to the other, regardless of the height or width of such a barrier.

Remarkably, an electron can accomplish this feat, even when the potential energy of the barrier exceeds the kinetic energy of the particle. Such behavior is known as quantum tunneling, and the flow of electrons is a tunneling current.

The current study has shown that single bases inside a DNA chain can indeed be read with tunnelling, without interference from neighboring bases. Each base generates a distinct electronic signal, current spikes of a particular size and frequency that serve to identify each base.

Surprisingly, the technique even recognizes a small chemical change that nature sometimes uses to fine-tune the expression of genes, the so-called “epigenetic” code.

While an individual’s genetic code is the same in every cell, the epigenetic code is tissue and cell specific and unlike the genome itself, the epigenome can respond to environmental changes during an individual’s life.

“These measurements confirmed the long lifetime of the complex, and also showed that the reading time could be speeded up at will by the application of a small additional pulling force,” said Robert Ros Ros.

Lindsay added: “The basic physics is now demonstrated and perhaps it will soon be possible to incorporate these principles into mass produced computer chips.” (ANI)