Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers develop ’fingerprinting’ for biological agents

30.08.2002


Scientists at Northwestern University have developed a powerful new method for detecting infectious diseases, including those associated with many bioterrorism and warfare threats such as anthrax, tularemia, smallpox and HIV.



A research team led by Chad A. Mirkin, director of Northwestern’s Institute for Nanotechnology, has invented a technique for creating thousands of DNA detection probes made of gold nanoparticles with individual molecules attached. Much like human fingerprints, these molecules act as unique signals for the presence of different biological agents. The new detection method, for instance, can easily distinguish smallpox’s distinct "fingerprint" from that of HIV.

"By providing a near infinite number of signals, this advance allows researchers to quickly and accurately screen a sample for an extraordinarily large number of diseases simultaneously," said Mirkin, also George B. Rathmann Professor of Chemistry.


Results, which include testing for genetic markers for six biological agents including hepatitis A, smallpox and HIV, will be published in the Aug. 30 issue of the journal Science. The new technology, which takes advantage of a technique called Raman spectroscopy, improves upon optical detection methods reported previously by Northwestern in Science.

Mirkin’s group has been pioneering the use of nanoparticles as a potential replacement for the more expensive polymerase chain reaction (PCR) and conventional fluorescence probes, the most widely used detection technology. It currently take days and sometimes weeks for results of genetic screening and disease diagnosis to come back from the laboratory.

"PCR was an extraordinary advance in diagnostics, but its complexity prohibits the development of easy-to-use diagnostic systems that can produce quick results in the field or in the doctor’s office," said Mirkin. "Once a disruptive technology like PCR is invented, it creates a challenge for scientists to develop something even better."

The new detection method involves designing probes for each disease agent. Each probe consists of a tiny gold particle approximately 13 nanometers in diameter. (In comparison, a human hair is 10,000 nanometers wide.) Attached to the particles are two key items: molecules that provide a unique signal (the "fingerprint") when a light is shined on them and a single strand of DNA designed to recognize and bind a target of interest, such as smallpox or hepatitis A.

These designer probes are used in conjunction with a chip spotted with strands of DNA designed to recognize different disease targets. If a disease target is present in the sample being tested, it binds to the appropriate spot on the chip. Corresponding nanoparticle probes latch onto any matches. The chip is then washed and treated with ordinary photographic developing solution. Silver coats the gold nanoparticles where a match has taken place. A laser is scanned across the chip, and the signals for the probes are recorded. A unique "fingerprint" can be designed for each biological agent.

"The silver enhances the signal by many orders of magnitude, creating a highly sensitive method for detecting DNA," Mirkin said. "Our technique seems to surpass conventional fluorescence-based methods in almost every category -- sensitivity, selectivity, ease of use and speed -- and has the potential to be very inexpensive." The "fingerprinting" method also offers a greater number of distinct signals than conventional methods, meaning more diseases can be tested for at one time.

Megan Fellman | EurekAlert!
Further information:
http://www.nwu.edu/

More articles from Process Engineering:

nachricht New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG

nachricht Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

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...

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

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>