A device that looks like a popular mass storage device when connected to a laptop can examine DNA in seconds, reports New Scientist.
Built by the British company Oxford Nanopore MiniION copes with the sequencing of the genome of bacteria or viruses in a few seconds. Larger genomes require more time, but the MiniION can also be used to test a sample of suspected cancer cells or to identify the genetic identity of a cadaver.
The demonstration – at the Advances in Genome Biology and Technology conference in Florida – successfully sequenced a simple PhiX virus with a genome of 5000 base pairs. This particular virus was chosen because its genome was the first ever sequenced.
Oxford Nanopore has also manufactured a larger device called the GridION for laboratory use. It works in the same way as the MiniION – DNA is put into a solution containing enzymes that stick to the end of each strand. Then, under the influence of electric current, enzymes and DNA end up in hundreds of holes in the membrane at the bottom of the solution.
Each hole is only 10 micrometers in diameter and contains a modified version of the alpha-hemolysin (AHL) protein, centered on a hollow, tubular space 10 nanometers in diameter. As DNA is drawn into this opening, the enzyme binds to AHL and separates the two strands of DNA, one of the separated strands being drawn into the opening. The unique electrical properties of each principle distort the current flow through the individual diaphragm openings in a manner that allows them to be identified.
The method has two great advantages – first, you do not need to duplicate DNA to get the right amount of it, and second – you can read DNA fragments of up to 10 units, while other techniques require cutting the DNA into shorter lengths. The reader is expected to go on sale this year at a price of $ 000 – affordable for most doctors.