Doctors and scientists wishing to decode a human genome can now do so in a day for US$1,000 a pop using the recently-released Ion Proton sequencer. With a price tag of $149,000, though, the machine isn’t cheap – nor is it the be-all and end-all of desktop gene sequencing. For one thing, the tiny $900 MinION sequencer should be available soon. Also, a team of scientists from Oak Ridge National Laboratory and Yale University have now developed a concept of their own, which could end up providing an even less expensive high-speed sequencer.
The concept, which was developed using theory, computer models and physical experimentation, involves something known as a Paul trap – a device that uses an oscillating electrical field to trap particles. To create their own Paul trap for DNA, the ORNL/Yale team used a radio-frequency electric field to create an “aqueous virtual nanopore” within a sample of water. Essentially, this means that they were able to isolate a very narrow cylindrical region of the water – other systems, by contrast, utilize nanopores bored through solid materials such as graphene.
While the water provided a stable environment for the DNA, the electric field kept it gently contained within the nanopore. As the DNA strand passed through the pore, the researchers were able to read its electrical signals to identify its bases.
Through the manipulation of external electrical fields, the size and stability of the virtual nanopore can be controlled, unlike the parameters of physical pores. The challenge now lies in incorporating the technology into a practical, affordable device.
“The low cost – if it can be achieved – would enable genomic sequencing to be used in everyday clinical practice for medical treatments and preventions,” said project director Predrag Krstic, of the ORNL.
A paper on the research was recently published in the journal Small.
Source: Oak Ridge National Laboratory