The chemical analysis of secretory vesicles has long been limited by the fact that many vesicles are analyzed together, resulting in an averaging of a population. Differences between vesicles within that population could not be detected. Wouldn't it be great if vesicles could be analyzed one at a time? You guessed it, this breakthrough has been recently achieved.

The technique of capillary electrophoresis (CE) was modified by Daniel Chiu, Sheri Lillard, Richard Scheller, Richard Zare, Sandra Rodriguez-Cruz, Evan Williams, Owe Orwar, Mats Sandberg, and Anders Lundqvist so that vesicles could be probed singly.

Contaminants on photoresist can be difficult to identify, especially if they are very thin, e.g., less than 0.5 μm. It is very doubtful at the 0.2 μm realm that histological or optical microscopy methods will work, There are several methods available to identify such contaminants1 each giving different degrees or type of information about contaminants.

What could be better than reflected or transmitted Nomarski differential interference contrast? Why, combining the best features of both and for very little cost. My intended use of the technique was for Nomarski reflection DIC microscopy. It will work, of course, with other types of reflection microscopy.

What this embarrassingly simple artifice accomplishes is to simultaneously add transmission capabilities to reflection observations with the result being improved viewing of delicate details, And, yes, because of the reflective front surface layer, the observer can study details on the bottom side of the specimen which is usually hidden from view. This requires focusing through the specimen and below the point of normal focus.

A typical electron microprobe printout of an oxide analysis shows weight percent concentrations of different elements in terms of their oxides, Fe is usually expressed as FeO. For minerals, it also shows calculated number of cations on the basis of an assumed (theoretical) number of oxygen atoms. For examplejn olivines, (Mg,Fe)2SiO4, the theoretical number of oxygen atoms is four and the sum of cations should add up to three if the analysis is good. However, in case of spinels such as magnetite, Fe3O4, which contain significant amounts of Fe2O3, the analysis total falls below 100 and the cation sum (based on four oxygens) exceeds the theoretical cation sum. in other words, the formula calculation shows an oxygen deficiency. Geologists use this information to calculate the amount of Fe2O3 in the spinel assuming the other cations have only one oxidation state.

In a recent microscopy discussion group, a correspondent questioned the use of a contrast enhancement method applied to a microscopy image for publication. What kinds of image processing, folk asked, are “acceptable” in a general sense? What kinds of image processing should be noted in the text or caption and what kind of images should be archived?

It is an interesting set of questions, and I face them wearing three hats, I am a forensic pathologist who performs forensic image interpretation in the investigation of homicide and assault, an anatomic pathologist with an interest in confocal microscopy, and a computer scientist with training in image processing and computer vision. Image processing is part and parcel of my everyday work. I use tools such as contrast enhancement, debarring, and photogrammetry for image interpretation. I build tools for visualization in my confocal work. I collaborate in the design of data acquisition devices for the evaluation of crime scenes and bodily injury.

The application of confocal laser scanning microscopy (CLSM) in the studies of biological materials is rapidly expanding because of the opportunity to produce sharp, high resolution images through optical sectioning and computer assisted 3-D reconstruction. At our institute CLSM is being used in a wide range of forestry and wood science studies.

Recently we investigated the potential usefulness of CLSM in characterizing biologically degraded wood. The following are images produced from an archaeological wood which has been buried in a wet environment (rice field) for nearly 2,000 years in South Korea and is apparently degraded by bacteria. In an attempt to develop suitable techniques which can be used for routine examination of fragile degraded wood with CLSM, we have compared two different embedding methods for their suitability in preserving the integrity of cells. The embedding media are paraffin wax and LR White resin.

The bubbled, popcorn or moth-eaten appearance of nuclei hampered accurate microscopic evaluation of bone marrow and lymph node biopsies. This artifact was also noticed in skin biopsies, but had little bearing on diagnosis. All aspects of specimen handling processing and staining were scrutinized and improved morphological detail was attained only after blocks were recut and allowed to dry completely before staining.

Paraffin wax is a mixture of (virtually) straight chain hydrocarbons. Note the word “mixture”. Unless one goes to the enormous lengths of purifying or searching for a fine chemical supplier, the wax will always be a mixture. I used a “pure” wax once as a standard for gas chromatographic studies on paraffin waxes. There is a relationship between hydrocarbon chain length and melting point, but as the waxes are always mixtures, melting points are never exact, either in the compounding or the measuring.