Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Weighty Viruses

05.12.2006
Weight determination of individual viruses with a miniature ion trap

Viruses are the simplest life forms on our planet, consisting of only DNA or RNA and a shell. After the prokaryotes (bacteria and archebacteria), viruses are the second most common type of organism. In our oceans they are the most common life form.

In order to gain a better understanding of the structure and characteristics of these genetically varied little organisms, it would be highly useful to be able to determine their masses and how much these vary within a given population. Researchers in Taiwan have now used very gentle ionization techniques and a miniaturized ion trap of their own devising to accurately analyze the masses of individual, intact viruses.

Previous methods for determining the masses of viruses had a margin of error of ±15%, which made them too inaccurate to ensure the resolution of small differences in mass. A team led by Huan-Cheng Chang has developed a new concept to attain higher precision. In order to determine their mass, viruses must first be converted to the gas phase, given an electric charge, and accelerated in an electric field. However, this process must leave the viruses intact. The researchers thus chose to use a very gentle method known as LIAD (laser-induced acoustic desorption). The virus particles are released from the sample by laser-induced sound waves. They are then caught in an “ion trap”.

... more about:
»Ion »Particle »Virus »mass

This is an electric field that holds charged particles prisoner by means of its special geometry and alternating voltage. Once trapped, the virus particles are ready for mass determination. Laser light is beamed into the ion trap. If a particle is present, it scatters the light. The scattered light can be detected through the transparent surfaces of the ion trap. A portion of the light is sent to a CCD camera, which records the flight path of the trapped particle. The rest of the light goes to a measuring device that precisely analyzes the scattering signal. The scattered light is different from the initial light beam because the virus particle in the electric field of the ion trap begins to oscillate. This oscillation depends on the mass (and charge) of the virus.

The team was thus able to determine the masses of three different types of viruses with diameters between 80 and 300 nm—with an astonishingly low margin of error of ±1%. The masses of the viruses can, in combination with other analytical processes, be used to infer how many building blocks are used to make up the shell of the virus or how many copies of the genetic material it contains.

These highly precise measurements were made possible by the special structure of the ion trap; instead of a classic quadrupole ion trap, Chang and co-workers chose to use a cylindrical ion trap (CIT). In this type of trap, the movement of the trapped ions is considerably more complex and not mathematically ascertainable. However, it has the advantage of a much simpler geometry. The team constructed a CIT with smaller dimensions than usual, optimized the geometry, and exchanged the usual terminal electrodes of the cylinder with transparent, electrically conducting plates. This special construction is what made application of the precise light-scattering technique for the mass determination of a single virus possible.

Author: Huan-Cheng Chang, Academia Sinica, Taipei (Taiwan), http://www.iams.sinica.edu.tw/web2006_e/Huan-Cheng%20Chang.html

Title: Microscopy-Based Mass Measurement of a Single Whole Virus in a Cylindrical Ion Trap

Angewandte Chemie International Edition 2006, 45, No. 48, 8131–8134, doi: 10.1002/anie.200603839

Huan-Cheng Chang | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.wiley.co.uk

Further reports about: Ion Particle Virus mass

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>