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 Fraunhofer researchers develop measuring system for ZF factory in Saarbrücken
21.11.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP

nachricht New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>