Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coming Soon: Tuberculosis Detection with a Chip?

29.07.2009
Lab on a chip: Highly sensitive detection of bacteria with magnetic nanoparticles and a miniaturized NMR method

Many of the new techniques based on nanotechnology that have been developed for faster and more sensitive detection of pathogens fail in day-to-day clinical use because they require complex sample preparation or measurement equipment, or simply cannot keep up with the large sample throughput in a clinic.

Researchers working with Ralph Weissleder at Harvard Medical School have now developed a very simple process for the rapid detection of pathogens that requires no further sample preparation. As reported in the journal Angewandte Chemie, this technique is based on magnetic nanoparticles and a nuclear magnetic resonance (NMR) measurement.

For their tests, the researchers used the bacillus Calmette-Guérin (BCG), a mycobacterium named after its developers, which was cultured from bovine tuberculosis bacilli in the early twentieth century. This is a weakened strain that is used as a live vaccine against tuberculosis. In addition, it serves as a model for the true tuberculosis pathogen Mycobacterium tuberculosis for research purposes.

The test is this simple: A sample is incubated in a solution that contains special magnetic nanoparticles. These nanoparticles consist of an iron core surrounded by a shell of ferrite, which is an iron oxide. The researchers attached anti-BCG antibodies to the surfaces of the nanoparticles. If BCG bacteria are present in the sample, the antibodies bind to them, thus equipping them with magnetic particles. The liquid is then introduced through microchannels into the tiny chamber of a microfluidic chip. At the exit of the chamber is a membrane that retains the bacteria while the rest of the solution, including excess magnetic particles, passes through. The bacteria thus become concentrated in the chamber.

The chamber is surrounded by a small coil, which produces the magnetic field required for nuclear magnetic resonance measurements (similar to a clinical MRI scanner). The bacteria, with their attached magnetic particles, influence the behavior of the nuclear spins of the water molecules in the chamber. This can be detected directly on the chip by means of the handheld miniaturized NMR system. It was thus possible to detect 20 bacilli in a sputum sample within 30 minutes.

Author: Ralph Weissleder, Harvard Medical School, Boston (USA), http://csb.mgh.harvard.edu/weissleder

Title: Ultrasensitive Detection of Bacteria Using Core–Shell Nanoparticles and an NMR-Filter System

Angewandte Chemie International Edition 2009, 48, No. 31, 5657–5660, doi: 10.1002/anie.200901791

Ralph Weissleder | Angewandte Chemie
Further information:
http://csb.mgh.harvard.edu/weissleder
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>