The use of barcodes on products, combined with the computer technology to read and track the subsequent data, has revolutionized inventory control in our society. Barcodes are commonly seen on items as large as automobiles and as small as pieces of candy. But if you need to track a large number of items that are microscopic in size, such as biologically relevant molecules (think genomics, proteomics, metabolomics, etc), then you need very small barcodes. Sufficiently small rods that can be marked as barcodes have been developed by Sheila Nicewarner-Peña, Griffith Freeman, Brian Reiss, Lin He, David Peña, Ian Walton, Remy Cromer, Christine Keating, and Michael Natan.

As progress indicators in electron microscopy, advances in spatial resolution and in spectroscopy probably attract most frequent attention. Improved user-friendliness has also been significant even when judged in comparison with scanned probe microscopy. Evidence for developments in in-situ microscopy at least equally impressive can be found by comparing the relevant sections of the book by Hirsch et al. and a more recent compilation.

Peter Hirsch's research group swiftly discovered the power and frustrations of in-situ microscopy. The cine film of dislocation motion observed in the earliest diffraction contrast studies, and attributed to the thermal stresses generated by the electron beam, was extremely effective in convincing the wider community that it was indeed dislocations that were being observed.

How do you comprehensively analyze the chemistry of a microstructure with an SEM equipped with an energy-dispersive x-ray spectrometer (EDXS)? Prior to the 1990's there would have been perhaps two distinct and commercially available solutions to this problem. Firstly, you could have collected a number of point spectra each with a large number of counts and individually analyzed each one. The positive aspect of this, in principle, is that for each point the elemental correlations are maintained (e.g., a given point contains Al and O). The potential problem is that the region of the point analysis in question is not representative of the microstructure as a whole or subtle differences between different points could be missed. Additionally, point analyses are quite subjective and prone to missing potentially important regions of the microstructure.

Immunofluorescence techniques using multicolor labeling and analysis of colocalization are essential for unraveling the structural and functional complexity of cells and tissues. Improvements in the capabilities of these techniques are dependent on the development of new fluorescent dyes and methods for attaching them to antibodies and other markers.

The Alexa Fluor® series of dyes developed by researchers at Molecular Probes, Inc. have optimized spectroscopic and physical properties that enable preparation of bioconjugates with consistently strong and photostable fluorescence output.

In the last few years Scanning Probe Microscopy (SPM) has become one of the primary tools of science and technology. In addition to topographical imaging, surface potential, conductivity, optical, ferroelectric and magnetic properties that can be studied down to the nanometer level. However, quantitative and sometimes qualitative studies of fundamental physical phenomena in meso- and nanoscale systems are often hindered by SPM imaging artifacts. Here we briefly discuss the principles of operation and the major sources of artifacts in electrostatic measurements by SPM.

One of the most well known techniques for local potential imaging is Scanning Surface Potential Microscopy (SSPM). SSPM is based on dual pass imaging. The grounded tip acquires surface topography during the first pass.

When we sit down at our microscopes, we assume that the environment is ideal - clean and quiet, with little to distract us from the sample. If an obvious distraction does occur, such as a bump to the instrument, or a big power surge, we look carefully and wonder, “Has the sample been damaged? Will the photograph be messed up?”

There are disturbances we may not notice, some of which are discussed in the Microscopy Listserver. One problem I have been involved in mitigating is the degradation of image quality (primarily decreased resolution) caused by vibration. We may not be aware if we have this problem, because the body is a lot less sensitive to vibration than a microscope. I will talk about the general nature of vibration, how it affects microscopy, and some thoughts on possible mitigation techniques.

The ability to immunologically link microscopic tags to specific proteins has produced major advances in all forms of microscopy. Initially researchers needed to make and label their own antibodies. This required a good working knowledge of immunology. Today labeled anitbodies are readily available from a variety of vendors. Although this has greatly facilitated the expansion of immunolabeling techniques, it has also led to their use by researchers with little or no background in immunology. While this is not a problem for simple, straightforward situations, the quality of data produced in more specialized experiments can suffer.

Microscopy labs have very quickly moved from keeping track of and storing thousands of samples and negatives “atoms,” to having to now deal with the same number of samples, and a few negatives, but in addition, we may now have thousands of digital images “bits.” In a two-year microscopy teaching program, which includes 18 microscopy courses, there are thousands of images, which must be collected from a variety of input devices running on various platforms. These must then be associated with different types of data files that need to be tagged to reports as well as being tagged to projects and courses. All of this information must be accessible, first to all those involved with doing the project, as well as to anyone associated with needing the results.