Would it be useful if you could examine a wet, perhaps even a living, specimen in the scanning electron microscope? Of course we think that this would be impossible, given the vacuum the specimen would be subjected to in the microscope. However, in the realm of materials research, the Environmental Scanning Electron Microscope (ESEM) is being developed. Apparently this instrument has not been fully appreciated and utilized by biologists.

As reviewed by Athene Donald, a pioneer in developing the ESEM, this instrument has been commercially available for a decade. It is still evolving as a useful tool in looking at materials such as cement, natural fibers, and aqueous dispersions. Applications of the ESEM. to biological Studies are extremely limited. However, studies on biological samples, even living cells, are possible (although not without problems and limitations).

Since publication of the classic text on the electron microscope laboratory by Anderson, the proliferation of microscopes with field emission guns, imaging filters and hardware spherical aberration correctors (giving higher spatial and energy resolution) has resulted in the need to construct special laboratories. As resolutions iinprovel transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs) become more sensitive to ambient conditions. State-of-the-art electron microscopes require state-of-the-art environments, and this means careful design and implementation of microscope sites, from the microscope room to the building that surrounds it. Laboratories have been constructed to house high-sensitive instruments with resolutions ranging down to sub-Angstrom levels; we present the various design philosophies used for some of these laboratories and our experiences with them. Four facilities are described: the National Center for Electron Microscopy OAM Laboratory at LBNL; the FEGTEM Facility at the University of Sheffield; the Center for Integrative Molecular Biosciences at TSRI; and the Advanced Microscopy Laboratory at ORNL.

Microscopy is one of the most important techniques in microbial ecology, since this is the most direct approach to examine the microbe's world from its own perspective and spatial scale. The value of quantitative microscopy in studies of microbial ecology can be increased even further when used in conjunction with computer assisted image analysis. There are two main advantages of using digital image processing and pattern recognition techniques in conjunction with microscopy for quantitative studies of microbial ecology. First, automatic image analysis reduces the amount of tedious work with microscopes needed to accurately quantify in situ morphological diversity, abundance and metabolic activity of microbes. Secondly, these techniques provide an important quantitative tool that can significantly enhance the polyphasic analysis of the structure, diversity, spatial features, and functions of complex microbial communities in situ without cultivation.

PowerPoint has traditionally been the software of choice for slide shows tit conferences and meetings. Its ease of use has made the program ideal, along with its universality among scientists and engineers.

The program does have its drawbacks, however. Most notably, it is saved in a format that essentially makes it unusable for any other purpose than that of a slide show. It cannot be used for publication, and, as many discover all too late, it is not the software of choice for making posters (both these phenomena go back to Microsoft's refusal to pay a license to Adobe for PostScript, the universally used “page description language” among publishers). The remainder of the drawbacks exist when the slide show needs to be distributed. Newer versions of PowerPoint can make HTML files for posting on a web site by using Save As under File, but saving in the PowerPoint format has not evolved as a way to view slide shows on the web.

The One-Ångstrom Microscope (OÅM) project was established at the NCEM to produce images at sub-Ångstrom resolution (O'Keefe, 1993). The project was implemented using a Philips CM300FEG/UT with hardware modifications designed to correct objective lens three-fold astigmatism and extend information transfer to 0.8 Ångstrom (O'Keefe et al., 2001a). A Gatan image filter (GIFTM) was used to bring the image magnification to more than three million times at the CCD camera to provide adequate real-space sampling.

Phase-contrast imaging in the HRTEM produces images with peaks at atom positions by extracting the spatial distribution of the relative phase from the electron wave. Usually, the electron wave is imaged by direct interference of diffracted beams at optimum focus (Scherzer, 1949).

Yeasts are single-celled eukaryotic microorganisms (generally about 5 to 10 microns in diameter) that divide by a budding process and are classified with the fungi. Yeast cells are ubiquitous in our environment and can be found on plants and in soil and water. Yeasts have considerable importance Ln industrial and agricultural settings, Saccharomyces cerevisiae (Figure 1) is also known as “bakers yeast” or “brewers yeast.” Specific strains of yeast are used to make pastries, bread, beer, ale, wine, distilled spirits, and industrial alcohol. In the paper industry, Candida utilis is used to break down die sugars from processed wood pulp. Yeast cells are also nutritious. In some societies, “cloudy” beer (containing yeast cells) provides essential B vitamins, minerals, and amino acids.

The protozoan parasite Giardia, an intestinal flagellate, has evolved an unique attachment organelle called the ventral adhesive disk (VAD). This attachment organelle mediates attachment of the trophozbite to the microviUous border (MVB) of intestinal absorptive cells, and production of lesions via attachment are thought to lead to diarrheal disorder characteristic of giardiasis. The VAD has contractile proteins arranged around it's circumference and it has been suggested that contraction of this area might function like a purse-string suture. The resemblance of the VAD to a suction cup has led to the hypothesis that suction or a negative pressure produced under the VAD by a grasping action might produce the adhesive force regulating attachment. To test whether or not the generation of a negative pressure is necessary for attachment, experiments were designed in which the substratum was fabricated to have an uneven surface, or the substratum was composed of different arrangement of pores.

Nearly five years ago, Representative Vernon Ehlers, in his report to Congress on a House of Representatives study entitled “Unlocking Our Future: Toward a New National Science Policy,” noted that the American public does not understand science and its practice. A major recommendation that emerged trom this study was the need to “make scientists socially responsible.“ This sentiment was echoed in a National Research Council's report, “Materials in a New Era,”, where Neal Lane, former Director of the National Science Foundation, was quoted as saying, “It is necessary to involve material scientists in a new role, undoubtedly an awkward one for many, that might be called the ‘civic scientist’.” Why the concern? The answer is clear. “Our prosperity, security, and health depend directly on the educational achievement of all students, not only those who will become scientists and engineers, but all workers, voters, parents, and consumers.”

Let's face it—uranyl acetate is the perennial bad boy of chemicals, at least from the standpoint of disposal. A necessary evil in the electron microscopy laboratory, it presents a quandary for those trying to comply with hazardous materials regulalions, an effort complicated by its nominal radioactivity. Disposal costs of radioactive materials can be daunting. A past posting to the Microscopy Society of America listserver gave an estimate of US$7000 per liter and local follow up indicated that, although probably high, that may not be an unreasonable figure. In these times of diminished subsidies and expectations of increased cost recovery by academic service facilities like ours, this is of paramount concern.

The Electron Microscopy Core Facility at the University of Missouri-Columbia follows guidelines issued by our campus Environmental Health and Safety (EHS) office regarding hazardous materials and their disposal.

Laser scanning confocal microscopy has been used to analyze cytological specimens for research purposes. However, for many pathologists, its application in diagnostic cytology still is terra incognita. In our laboratory, confocal microscopy has been used for seven years, mainly to solve problems in cervical cytology, in breast aspirates, and for endometrium cytology.

In contrast to histology where we can cut new sections from the block, the cytologic sample is often limited to one smear. Accordingly, when we wish to expand our diagnostic possibilities, we have to extract the desired additional information from that single smear. This is possible by first de-staining the original smear and subsequently re-staining it. In this article, we describe how we restain old slides with the fluorescent dyes Ethidinm Bromide and Eosin, a DNA/protein stain, resulting in staining patterns comparable to the diagnostic Papanicolaou and Giemsa methods in that mere is an optimal distinction between nucleus and cytoplasm.