Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Light games with DNA

13.12.2010
The toolbox for imaging DNA now comes with an artificial DNA fluorescent base that can be ‘switched off’

The diagnosis of hereditary diseases and the identification of genetic fingerprints hinge on high-sensitivity DNA imaging biotechnologies. These imaging tools detect specific genes in cells using fluorophores—fluorescent tags that can illuminate DNA structures—and quenchers that interact with these tags to prevent them from emitting light, effectively working as an ‘off switch’.

In a development that expands the detection toolbox and the genetic alphabet, a team led by Ichiro Hirao from the RIKEN Systems and Structural Biology Center, Yokohama, has now designed an artificial base pair between a fluorophore (Dss) and quenchers (Pn and Px)¹. This method incorporates the pair into complementary DNA strands using polymerases and demonstrates that either Pn or Px can decrease the fluorescence of Dss upon hybridization.

Hirao and his team previously developed artificial base pairs involving Dss because of its strong fluorescence, which could illuminate DNA and RNA structures. “This time, we can put out the candle lit by Dss using the quencher as its pairing partner at will,” he says.

Hirao notes that this ability is unique because fluorescent dye Dss and quencher Pn face each other on their respective ssDNA strand, forming an artificial DNA base pair that also works in biological systems. He says that this close proximity results in strong ‘contact quenching’ of the fluorophore.

Usually, researchers have attached fluorophores and quenchers to natural bases through a linker that mediates so-called fluorescence resonance energy transfer (FRET) between dyes. However, this process lacks efficiency compared to contact quenching. Also, according to Hirao, unlike the Dss–Pn system, typical fluorophore–quencher pairs cannot be introduced at specific positions in DNA strands using polymerases, limiting their applications.

After establishing that the pairs were compatible with natural DNA synthesis techniques, Hirao’s team integrated the Dss–Pn pair in the stem of molecular beacons—hairpin-shaped single-stranded DNA (ssDNA) structures that fluoresce upon hybridization with DNA targets. They found that the beacons detected the targets with high sensitivity and differentiated ssDNA containing one mismatched base.

Next, the researchers tested the performance of Dss–Px in polymerase chain reaction (PCR)—a powerful DNA amplification technique. Dss-bearing ssDNA fragments became less fluorescent upon assimilation of Px into synthesized DNA chains, allowing the team to monitor the amplification process in real time.

“One of our present tasks is to apply this system to in vivo cell experiments,” says Hirao. “If it is possible, we will be able see the on–off of a specific gene expression.”

The corresponding author for this highlight is based at the Nucleic Acid Synthetic Biology Research Team, RIKEN Systems and Structural Biology Center

Journal information

1. Kimoto, M., Mitsui, T. Yamashige, R., Sato, A., Yokoyama, S. & Hirao, I. A new unnatural base pair system between fluorophore and quencher base analogues for nucleic acid-based imaging technology. Journal of the American Chemical Society 132, 15418–15426 (2010).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>