DNA nanoball strategy, a low-cost technology

Subject: Science and technology

Section: Biotechnology

Source : Geneng News

Context:

With just a room-temperature “pot,” a sprinkling of molecules, and a simple electrical device, pathogen DNA detection can now be achieved in under an hour anywhere.

DNA nanoball strategy:

A new platform using nucleic acids-based diagnostics showcases a way to detect pathogens more quickly in the field.
Through loop-mediated isothermal amplification technology (LAMP), the approach creates nanoballs out of pathogens’ DNA that can then be identified through electrical signaling, using the MEMS (microelectromechanical systems)—the technology of microscopic devices incorporating both electronic and moving parts.
This method creates concatemers—long DNA molecules that contain multiple copies of the same DNA sequence linked in series—that fold into themselves to produce micrometer-sized balls of DNA from target viral or bacterial nucleic acids. These so-called “DNA nanoballs” are the size of certain bacteria and are detectable by a microscope and electrical impedance.
The design does not need laboratory techniques to support diagnosis. It is a low-cost technology that can be widely deployed and scalable.
Advantages:
- Detects viruses when infected people are pre-symptomatic.
- Viruses can be detected when there are less than ten copies in a nasal swab sample.

DNA nanoball sequencing:

DNA nanoball sequencing is a high throughput sequencing technology that is used to determine the entire genomic sequence of an organism.
The method uses rolling circle replication to amplify small fragments of genomic DNA into DNA nanoballs.
Fluorescent nucleotides bind to complementary nucleotides and are then polymerized to anchor sequences bound to known sequences on the DNA template. The base order is determined via the fluorescence of the bound nucleotides.
This DNA sequencing method allows large numbers of DNA nanoballs to be sequenced per run at lower reagent costs compared to other next generation sequencing platforms.
A limitation of this method is that it generates only short sequences of DNA, which presents challenges to mapping its reads to a reference genome.