Better microscopic resolution

Antoni van Leeuwenhoek

van Leeuwenhoek would be envious! Image via Wikipedia

You may recall the article I found several weeks ago about a modification of light microscopy that gave us an improvement over the resolution of light microscopy.  Stephanie V. found an article about a new method for microscopy:

This article, “Microbial Life in The Ocean’s Desert,” by Alyson Santoro is not exactly on any specific microorganism but it does talk a lot about this microscope called a nometer-scale secondary ion mass spectrometry, or nanoSIMS, which combines a microscope and mass spectrometry. For this article they were particularly looking at marine microbes in the deserts and how they use nitrogen and carbon compounds, and with the help of this microscope they are able to do this. I think this microscope is just a bit more powerful than any we have here at York College because it allows these scientists to actually view the sharing of the nitrogen between the microbial symbionts and the diatoms, which are single celled algae. The way that this microscope is particular to these microorganisms because it uses, several liters of seawater which is where the microorganisms are and then a stable isotope-labeled nitrogen gas is added, and the bottles with the mixture are incubated in sunlight. At the end of the experiment, you filter the seawater onto special gold- and palladium-coated filters. Then back in Bremen, Germany, where the only nanoSIMS facility is in the world, they will examine the filters with a microscope to find cells they are interested in, and then load the samples into the nanoSIMS. The way the nanoSIMS then works is by, “the nanoSIMS uses a cesium (Cs+) ion beam to bombard the sample on the filter with Cs ions. When this happens, charged particles (the secondary ions) are ejected from sample and can be collected in special detectors that are tuned to detect specific masses, corresponding to different elements and their isotopes. The end result is a colorful “map” that shows in which cells, and where in those cells, the labeled nitrogen ends up,” (Santoro, 2011). So basically this nanoSIMS helps these scientists see how the nitrogen is being shared between these organisms, which is pretty cool considering the size of these organisms in the first place which is usually less than five micrometers long!


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on May 5, 2011, in Microbes in the News and tagged , . Bookmark the permalink. Comments Off on Better microscopic resolution.

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