The atomic force microscope (AFM) is being utilized in even more clever ways to reveal details of molecular structure and function. As an example, Julio Fernandez and Hongbin Li have used the AFM in the force-clamp mode to monitor the folding trajectory of a single protein. They have demonstrated in a unique way in which a single protein behaves when put under tension, and then what happens when the tension is relieved.

Fernandez and Li linked several molecules of ubiquitin, a small protein, together to form a polyubiquitin chain. With one end of the chain attached to a substrate, the tip of a soft cantilever of the AFM attached to a single protein, and from one to nine ubiquitin molecules were picked up.

Electron microscopy (EM) of fully wet samples is a valuable tool for studies in the material, medical and biological sciences. In order to appreciate the natural structures of tissues or materials they should be examined in their native wet state, as opposed to a dry form that incorporates artifacts of sample processing. Viewing and analyzing wet samples at high resolution has undergone a significant improvement only recently due to the innovative WETSEMTM technology developed by QuantomiX.

Clathrin-coated vesicles are the shuttle containers within cells. The vesicles carry lipids and proteins between membrane-bound compartments. Clathrin forms a cage-like structure around the membrane-bound vesicle that is pinched off from the plasma membrane (in endocytosis) or a membranous component of the cytoplasm. Clathrin recruits cargo that is within a vesicle through intermediary proteins known as adaptors that help select membrane-anchored protein and form an interface between the clathrin cage and the membrane bilayer.

Gene expression has been visualized for a few decades, but in static forms such as blots and gene chips. Susan Janicki, Toshiro Tsukamoto, Sim one Salghetti, William Tansey, Ravi Sachidanandam, Kannanganattu Prasanth, Thomas Ried, Yaron Shav-Tal, Edouard Bertrand, Robert Singer, and David Spector have recently designed a cell line in which gene expression can be observed with stunningly accurate spatial and temporal resolution. Gene expression is a cascade of events beginning with transcription of RNA from the DNA template and ending with translation into a protein sequence. Janicki et al. were able to visualize the entire process at the levels of DNA, RNA, and proteins in living cells!

Green fluorescent protein (GFP) and related molecules have been important signal molecules for cell biologists because they emit a bright signal to mark the position of tagged structures as well as changes in calcium and proton concentrations. Related molecules even emit in different colors. Now Hendrik Dietz and Matthias Rief from the Technical University of Munich have given us a detailed look at the "energy landscape" of GFP with the promise that it may also be useful indicator for forces.2 In this context, energy landscape refers to a three-dimensional map of the energy levels of the molecule as it is transitioned from its native state to an unfolded state.

The general consensus has been that the shells of mollusks form outside of cells. Akin to bone formation in vertebrates, an organic matrix is secreted by cells and the inorganic material is deposited within this matrix in an organized way. Andrew Mount, A.P. (Hap) Wheeler, Rajesh Paradkar, and Dennis Snider have now found convincing evidence that blood cells (specifically a class of granulocytic hemocytes) may be directly involved in shell crystal production for oysters.

Plants that are used for taxonomic research are generally preserved by drying them out while they are being pressed flat for easy storage. This pressed plant material, is placed in a herbarium, in phylogenetic order, based on the species, genus, family and order designations.

Herbaria are essential for the study and verification of plant classification, the study of geographic distributions, and the standardizing of taxonomic nomenclature. Lately, herbarium materials have been utilized in biochemical and genetic studies. The key to these studies is the state of preservation of the plant material. The preservation of the reproductive and vegetative structures (hairs, stomata, cuticle, etc.), internal anatomy (vascular tissue size and arrangement), biochemistry and genetic material is essential to make accurate observations, to collect representative data and answer pertinent research questions.

The continued focus on improving materials, combined with the fact that it is now commonly understood that material properties are affected by characteristics at the atomic level, give rise to the need to characterize and image at the best resolutions possible. The (Scanning) Transmission Electron Microscope ((S)TEM) has the capability to image structures with atomic resolution and provides, at the same time, information on the chemical composition, bonding and electronic structure of the material. The nanoresearcher's continued need for the ultimate resolution has accelerated the development of next generation electron optics and technology.

Whether you encounter electron powder diffraction patterns everyday, or run across them only rarely, interpreting them may require a bit of preparation. But it's easy to lose track of the numbers for your microscope's camera constant, not to mention the bewildering array of lattice parameters and symmetries that one may encounter in the microscope. In that context, we describe overlays you might want to assemble for measuring camera constants, and for recognizing crystal systems most likely to yield electron powder diffraction patterns in your lab. Pulling this out of a drawer and/or computer folder thereafter might help you come up with quick answers, even if you haven't thought about analyzing diffraction data for quite a while.

The beginning of metallurgy in the Old World is characterized by hammering native metals such as gold, copper and meteoric iron. Owing to the need of annealing the metal, for softening it after cold working, pyrometallurgy, the use of fire for producing metals from ores, could have been found by trial and error. Parallel to the rise of metallurgy is the use of a campfire (low temperature: max. 800°C) for baking clay-objects, which also seems to be an additional origin of metallurgy. The very first piece of molten copper-ore, dating back to the 7th millennium BC, was found in Catal Hoyiik, Turkey, together with hammered native copper and beads made of galena (PbS), initially mistakenly thought to be metallic lead.

The Field Emission SEM was introduced to improve imaging resolution available with conventional SEMs with a tungsten source. Thermal assisted or Schottky Field Emission SEMs were introduced in s the nineties by a number of companies as a stable source to overcome the beam instability of the cold FESEMs introduced earlier. The Gemini® based Field Emission SEM launched by Zeiss 12 years ago has been designed from the beginning as a high stability FESEM with a relatively large multi-ported chamber. The drive to develop Gemini® technology was the need for a FESEM capable of ultra-high resolution performance over the entire accelerating voltage range that also possessed the flexibility needed for a wide range of analytical applications.

The Space Shuttle Columbia was returning from a 16-day research mission, STS-107, with nominal system performance prior to the beginning of the entry interface into earth's upper atmosphere. Approximately one minute and twenty four seconds into the peak heating region of the entry interface, an off-nominal temperature rise was observed in the left main landing gear brake line. Nearly seven minutes later, all contact was lost with Columbia. Debris was observed periodically exiting the Shuttle's flight path throughout the reentry profile over California, Nevada, and New Mexico, until its final breakup over Texas. During the subsequent investigation, electron microscopy techniques were crucial in revealing the location of the fatal damage that resulted in the loss of Columbia and her crew.

Plum Island Animal Disease Center, located on a small island off the coast of Long Island's North Fork, has been clouded in mystery and misinformation for years. Often the topic of conspiracy theorists, this secret place has generated many myths—from aliens to anthrax and pink eels to secret submarines. But the truth of the center's mission is far less colorful yet far more crucial to the state of the nation's agriculture.

In June 2003, operational responsibility for the Plum Island Animal Disease Center (PIADC) transferred from the United States Department of Agriculture (USDA) to the United States Department of Homeland Security (DHS), and PIADC became the core of the DHS effort to protect US livestock from foreign animal disease agents.

The late 1940s marked the appearance of the first publications using transmission electron microscopy (TEM) and by 1950, with improved embedding and sectioning methodology, reports began to include mammalian tissues (PubMed). However, 15 years lapsed before morphometry and stereology were integrated into TEM studies (Loud 1965; Elias 1971; Weibel 1969). The utility of a quantitative approach to electron microscopy was obvious, but its popularity has waxed and waned considerably over the last half century; its staunch supporters, however, have stayed the course (Weibel 2001; Diaspro 2004). Early computers, though slow and unreliable, brought some degree of automation to morphometry in the 1980s, but did little to ease tedium or increase accuracy (Caruntu 2002).

Fluorescent fusion proteins are widely used to visualize the localization of proteins in worms, fish, flies and tissue culture cells. We have used two different methods that use high pressure freezing (HPF) combined with correlative light microscopy (LM) and TEM. The first method uses fluorescence from live organisms immobilized in agarose followed by HPF and standard freeze substitution in dry solvent with osmium. This pre-embedding method optimizes ultrastructural preservation. A second, post-embedding method preserves fluorescence and immunoreactivity from embedded and polymerized thin sections. Here we describe post-embedding fluorescent integrated TEM images (F-TEM).

By using a scanning transmission electron microscopy (STEM) detector, the information limit for the Gemini® FESEMs can be extended beyond the nanometer range. A resolution of 0.8 nm at 30kV is now readily attainable and gives additional nanoscale information compared to conventional SEM detectors. The resolving power of the combined FESEM/STEM can be used to save processing time on TEM systems and enables high sample throughput for quality assurance applications and standard type measurements. The transmission mode of the FESEM has the advantages of avoiding chromatic aberration, allowing for a larger aperture so that higher transmission, signal-to-noise ratio and contrast enhancement due to the lower electron energy (10 - 30kV) can be obtained.

Traditionally a scanning probe microscope (SPM), such as the atomic force microscope (AFM), affords spectacular images of surfaces at the nanometer scale. With advanced developments in scanner design, probe manufacturing and force sensor technology it is now possible to make quantitative metrological measurements with an SPM. Quantitative metrological measurements that are possible include: a) dimensional measurements of micro/nano fabricated structures, b) surface texture of surfaces having RMS values of only a few angstroms, and c) measurements of the number of grains, and particles on a surface as well as grain and particle sizes, areas, volumes, and distributions.

The ability of infrared microscopy to combine the chemical fingerprinting of FT-IR (Fourier Transform infrared) spectroscopy with the spatial resolving power of microscopy has led to its widespread use in numerous industries during the past two decades. The recent incorporation of imaging detectors into infrared microscopes has led to an increasing range of applications for the technique. The increase in spatial information provided by FT-IR imaging microscopes has also allowed image analysis techniques developed in light or electron microscopy to be utilized for the first time. This article will discuss FT-IR microspectroscopy and present some of the current applications.The ability of infrared microscopy to combine the chemical fingerprinting of FT-IR (Fourier Transform infrared) spectroscopy with the spatial resolving power of microscopy has led to its widespread use in numerous industries during the past two decades. The recent incorporation of imaging detectors into infrared microscopes has led to an increasing range of applications for the technique. The increase in spatial information provided by FT-IR imaging microscopes has also allowed image analysis techniques developed in light or electron microscopy to be utilized for the first time. This article will discuss FT-IR microspectroscopy and present some of the current applications.

Image quality of 'secondary electron imaging' has been an ongoing operational issue with the variable pressure range of scanning electron microscopes (VPSEM), including the extended pressure range environmental or SEM. A second question that has received considerable attention concerns charge cancellation on insulators in VPSEM with particular reference to effects of charging on x-ray microanalytical results.

New and novel fast scanning microscopes with much enhanced image capturing and image analysis tools can dramatically extend the analytical power of traditional light microscopy by converting it to what one may call "virtual microscopy" (VM). One of the most important application fields of VM is connected to medical pathology. Here one can introduce the concept even to routine diagnostics in the day-to-day clinical environment. Further, over an intranet network, VM allows quick and easy access to the "virtual slides" database at any time and at any place. Another important aspect is the prospect that long-term archiving in large regional hospitals will be greatly facilitated.