A recent article by Matthias Rief, Filipp Oesterhelt. Berthold Heymann, and Hermann Gaub concluded with this sentence: "Single molecule force spectroscopy by AFM has proven to be a powerful addition to the nanoscopic piconewton toolbox," Everything about that conclusion is tiny. Clearly, the atomic force microscope (AFM) has given us a tool to examine structure at or near the atomic level. Earlier work from Gaub's laboratory, reviewed in this column, demonstrated that the AFM could directly measure the binding force between single molecules of biotin and avidin. This established that the AFM could be used as a tool to measure forces, not just observe structure. Their most recent experiments has added to this tiny toolbox.

The chain of events that led to the invention of the electron microscope is an interesting story by itself. This chain has a common theme, namely electrons, and its first link is a natural phenomenon: lightning.

A flash of lightning generates a stream of electrons with a potential energy difference of 100 to 200 megavolts between clouds acting as electrodes, Benjamin Franklin envisioned this as a source of energy and tried to snatch electricity from the skies, but this proved to be too dangerous.

At the beginning of the century, lightning was a problem for electrical utilities because it produced surges that disrupted the steady flow of electricity along high tension lines. For this reason, in 1929 a high tension laboratory was founded in Germany with the sole aim of finding a way to test electrical transmission lines so as to make them capable of withstanding the lightning surges.

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The EOE is a complementary online community based around the creation, sharing, and use of teaching resources that incorporate Java applets for web-based learning. Java applets are small, easy-to-use programs written in Sun Microsystem's Java programming language. Using virtually any computer equipped with a standard web browser, educators can access hundreds of teaching and curriculum development tools for use in the classroom, for research, or in other educational endeavors.

As the number and variety of ceramic materials have grown so rapidly in the last few decades, ranging from silicon nitride structural ceramics to the perovskite superconductors to the ferroelectric oxides to semiconducting sensors, the number of scientific and technical issues has also grown rapidly. Many of the basic questions relate to the role the microstructures play in determining the observed physical behavior, but increasingly it is not the geometric properties of the microstructure that are of central concern but rather compositional variations and associated electrical characteristics.

These notes address conventional specimen preparation for higher plant tissues. While in many cases freeze-substitution has been shown to be a superior method, the equipment required is not generally available in most electron microscopic laboratories, Thus, the more conventional procedures outlined herein have been found to work satisfactorily for most leaf material, and have been most successful in the fixation and embedment of small root slices (from near the root tip), An adjustment of the osmotic pressure may be necessary if the plant material used is highly vacuolated and if there is an exceptionally high water content.

I use immunocytochemical detection schemes that employ the use of primary and secondary antibodies for either tissue sections or whole mount preparations in order to study the in situ distribution of proteins and labeled nucleic acids. As the antibodies are either laboriously generated, or represent costly purchases. I have sought a protocol that minimizes the volume of antibody solution needed. Additionally I need a protocol that involves a quick, thorough, and gentle application and removal of the antibody solutions (mm the specimen with no danger of the specimen drying out during the one or two hour incubations. After trying many various schemes 1 have settled into the use of a procedure which very effectively retains the antibody solution on the specimen without damaging the delicate sections or whole mounts, and which is easy to add and remove.

Microwave slide drying can be an extremely useful tool in the laboratory as it can cut the time it takes to dry slides without compromising the morphology or staining quality.

One important factor is to always use some type of Plus slide. We have found in trials that when using these slides we have not had tissue fall off the slide and we specialize in eye tissue which is notorious for (ailing off the slide.

Individual BHK-21 (Baby Hamster Kidney-21} cells growing on 25 mm photo-etched alpha-numeric glass coverslips (Belico Co.) are identified by phase contrast microscopy and photographed. (Saredi, Howard and Compton, 1995), This method should work for other cell lines, but likely will require some empirical adjustment of the times, concentrations, and pH.

NetSEM for LEO 400 series microscopes makes the remote control of an SEM over the internet or telephone line a reality. Unlike current commercially available remote control applications which duplicate a Windows session on a remote PC, NetSEM presents a customizable interface which is accessed via a Web browser and uses lossy compression techniques to optimize SEM image transfer over high, variable and low bandwidth connections.

The of use this material goes back to the days when fractography was done by TEM because SEM was not commercially available, There is, therefore, some very old literature on how to use the material, but since most of it is art, anyway, most current authors assume that the reader is generally familiar with the technique.

There are actually two purposes in using this material. Even for relatively small samples, it may be necessary to remove corrosion products in a nondestructive manner. In my opinion the best way to do this is to use acetone-softened cellulose acetate, which will remove the corrosion product but leave what is left of the metal.