Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NRL researchers report a forceful new method to sensitively detect proteins

18.03.2009
Scientists at the Naval Research Laboratory (NRL) recently reported the detection of toxins with unprecedented speed, sensitivity, and simplicity. The approach can sense as few as a few hundred molecules in a drop of blood in less than 10 minutes, with only four simple steps from sample to answer.

The sensitive new test builds on NRL's patent-pending Fluidic Force Discrimination™ (FFD) assay. In a FFD assay, a chip has arrays of receptor molecules such as antibodies that capture toxins or other target molecules that have been labeled with micrometer-sized beads.

By encapsulating the chip in a microflow chamber, the fluid flow can be controlled to apply just enough force to remove beads that are resting on the array but not truly labeling a toxin. "In this way," explains lead author Dr. Shawn Mulvaney, "very few molecules can be detected, because there is almost no background signal." "And because we can get the background so low," he adds, "FFD assays are very specific, with very few false positives."

In the current report, the NRL researchers have adapted FFD assays to detect a protein toxin at concentrations as low as 35 attomolar—over 1000 times more sensitive than existing commercial tests for proteins. In the new assay, dubbed "Semi-Homogeneous Fluidic Force Discrimination," the antibody-coated microbeads are mixed directly with the sample and rapidly collect the dilute toxin molecules. The toxin-coated beads are then injected into the microflow chamber where they are captured by the receptor designed for that target. Finally, beads that don't belong are removed with fluid forces. The remaining beads are all attached by the toxin to the surface and may be counted to indicate the toxin concentration. NRL has developed both electronic and optical systems to count the beads, along with reusable plastic test cartridges.

The paper won the award for Most Original Contribution at the Tenth World Congress on Biosensors, held in Shanghai, China, May 14-16, 2008 out of 978 competing papers. The awards committee noted that it was the combination of outstanding performance and modeling that set the NRL paper above the competition. The researchers developed a detailed mathematical model that includes every step of the assay, which was critical to maximizing the capture and the overall sensitivity they thereby achieved. "When very few molecules are present in a sample, such as a drop of blood," comments NRL's Dr. Paul Sheehan, "it is critical to try and capture and count every single one." Dr. Paul Sheehan emphasized that "target capture and delivery tends to be a neglected aspect of biosensor design."

"A key advantage of the NRL platform," explains Dr. Lloyd Whitman, now at the National Institute of Standards and Technology, "is that it can be applied simply even to the most challenging samples, such as serum, blood, urine, or food." "We expect it to have broad applications in medical and veterinary diagnostics, food and water testing, and national security." Dr. Mulvaney concludes, "Based on the simplicity of the method, we envision small, portable systems for point-of-care testing, field monitoring, and use by first responders."

Donna McKinney | EurekAlert!
Further information:
http://www.nrl.navy.mil

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

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

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>