Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Test for Germs

07.04.2011
Fluorescing DNAzymes detect metabolic products from bacteria

Germs in food, bioterrorism, drug-resistant bacteria and viruses—these are the problems of our time that make early detection of pathogens particularly important.

Whereas conventional methods are either slow or require complex instruments, Yingfu Li and a team at McMaster University in Hamilton (Ontario, Canada), additionally supported by the Sentinel Bioactive Paper Network, have now developed an especially simple, universal fluorescence test system that specifically and rapidly detects germs by means of their metabolic products. As the researchers report in the journal Angewandte Chemie, It isn’t even necessary to know which substance the test is reacting to.

Traditionally germs have been detected through microbiological methods, which are very precise but can take days or weeks. PCR- or antibody-based methods are rapid but require many steps and special equipment. “We were motivated to develop an especially simple, but very rapid and precise method,” says Li. “It must also be universal, meaning that it should be possible to develop tests for any desired germ using the same principle.”

... more about:
»Angewandte Chemie »DNA »DNA molecule »DNAzyme »E. coli »RNA »germs

“When a pathogen is metabolically active and multiplying in a given medium, it releases many substances into this environment. These are what we want to use,” says Li. The idea is to produce DNAzymes that react to a pathogen-specific product. A DNAzyme is a synthetic one-stranded DNA molecule with catalytic activity. Making a large pool of DNA molecules with random sequences and subjecting these to repeated selection and amplification steps allows for the development of molecules with the desired property.

At the core of the conceptual DNAzyme is a single RNA nucleotide. To its right and left are a fluorescing dye and a quencher. A quencher is a molecule that switches off the fluorescence of a dye when it is nearby. The researchers developed a DNAzyme that binds to a specific metabolic product from E. coli bacteria, which causes the DNAzyme to change its shape. In this altered form, the DNAzyme has RNA-splitting capability and cuts its own strand at the location of the RNA nucleotide. This separates the quencher from the dye, which begins to fluoresce. The fluorescence indicates that E. coli is present in the sample. This DNAzyme does not react to other bacteria.

“Through targeted selection, it should be possible to find a specific DNAzyme for any desired germ,” says Li. “It is not necessary to know what the metabolic product is, or to isolate it from the sample.” By using a common cell culture step, it is possible for the pathogens in a sample to multiply before the test, which allows for detection of a single original cell.

Author: Yingfu Li, McMaster University, Ontario (Canada), http://www.science.mcmaster.ca/biochem/faculty/li/
Title: Fluorogenic DNAzyme Probes as Bacterial Indicators
Angewandte Chemie International Edition 2011, 50, No. 16, 3751–3754, Permalink to the article: http://dx.doi.org/10.1002/anie.201100477

Yingfu Li | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.science.mcmaster.ca/biochem/faculty/li/

Further reports about: Angewandte Chemie DNA DNA molecule DNAzyme E. coli RNA germs

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>