Never before has the nano-scale world of viruses and proteins been so visible. A team led by scientists at IBM Research has developed a new imaging technique based on the same principles used in magnetic resonance imaging, or MRI, which is routinely used in hospitals. But the new process has 100 million times better resolution than a conventional MRI, allowing researchers to construct 3-D images of individual tobacco mosaic viruses, which are only 18 nanometers in diameter. “This technology stands to revolutionize the way we look at viruses, bacteria, proteins, and other biological elements,” said IBM [researcher] Mark Dean…. This advancement was enabled by a technique called magnetic resonance force microscopy (MRFM), which relies on detecting ultrasmall magnetic forces [CNN].
The MRFM process hasn’t captured images of the smallest objects ever: Techniques like atomic force and scanning tunneling microscopes have provided images of individual atoms. (An atom is about one-tenth of a nanometer in diameter). But these techniques are more destructive of biological samples because they send a stream of electrons at the target in order to get an image. And these microscopes cannot peer beneath the surface of the Lilliputian structures [The New York Times]. Researchers say the new 3-D technique will be enormously valuable for the study of protein structures.
As described in the Proceedings of the National Academy of Sciences [subscription required], MRFM works by measuring the minuscule vibrations caused by hydrogen atoms that are exposed to an oscillating magnetic field. The researchers placed the virus particles on the tip of a microscopic cantilever arm and positioned the tip close to a strong, tiny, fixed magnet. As the magnetic spin axes of the hydrogen atoms in the viruses flipped up and down, the atoms were alternately attracted to and repelled by the fixed magnet, thus creating the pushing and pulling on the arm. The strength of these forces indicated how many hydrogen atoms were at a given spot in the virus, and moving the tip around built up a 3-D representation of the virus shape [Science News].
Researchers say the latest advance is a step towards taking 3-D snapshots of individual molecules and the atoms that comprise them. “The real significance of this is it shows that the limits of MRFM haven’t been reached, and they’re still on the way to doing an atomic imager,” says Jonathan Jacky, a research scientist at the University of Washington. “An atomic-scale imager would be one of the most significant scientific instruments ever. It would be on the same level as the telescope or the light microscope. That’s what’s really exciting about this” [Technology Review].
Related Content:
DISCOVER: The Sensitive Touch examined the first attempts to develop MRFM back in 1995
DISCOVER: Physicists Build the World’s Smallest Transistor
80beats: Dime-Sized Microscope Could Be a Boon for Developing World Health
Image: IBM
January 13th, 2009 at 1:31 pm
I have to take exception to paragraph two. Atomic Force Microscopy uses zero electrons. It uses a cantilever arm with a turntable-like ‘needle’ on the end of it that uses coulomb forces and a laser beam bounces off the back of the cantilever to measure surface topology non-destructively. The tip of a AFM never actually touches the sample, it just floats on the cushion of electrons of the surface atoms of the sample.
AFM can’t use electrons, because it doesn’t use a vacuum system, it operates in plain old air (or submersed in liquid).
STEM (Scanning Tunneling) does use electrons, and will cook a biological sample after a few minutes of study unless you’re using cryomicroscopy to chill the sample to liquid nitrogen levels, which keeps the sample more in-tact for study (but will eventually be contaminated or destroyed).
However, this new IBM technology will likely revolutionize microscopy, because with FMRI, we see the INSIDES of peoples brains and bodies. This technique in microscopy may at some point allow us to image the insides of objects, as Jonathan Jacky explains. Hail to IBM, one of the hottest places around if you’re into nanotech.
-an Electron Microscopy student
January 13th, 2009 at 1:32 pm
Getting a better look at these virus’ will alloy doctors to get a better look and possibly be able to treat them more affectively.
January 13th, 2009 at 1:35 pm
Nuestra tecnología asombra, pero el más creamos para curar el más destruimos la sociedad.
January 13th, 2009 at 2:32 pm
this article is really cool because of the fact that this world is moving and its moving fast 100 years ago we didnt have lights we had candles and we didnt have color tv now we have all that plus more and i just think it is really cool how far we have come in this world and i know there is more to come
January 13th, 2009 at 2:47 pm
Just think about it in 2030 we might start liveing on the moon because we find new technique every day.
January 13th, 2009 at 2:53 pm
I like this article because knowing we are getting one step closer with this technology to help out people who probably got health problems is really helpful…maybe it helps out doctors more!!
January 13th, 2009 at 3:02 pm
if we get a better look at t he viruses and study them more, it could allow doctors to get a better look and it could help the doctors treat the virus!
January 14th, 2009 at 4:47 am
no pics – didn’t happen…