Life Sciences Commons^™

Preparation Of Biological Samples For Transmission X-Ray Microanalysis: A Review Of Alternative Procedures To The Use Of Sectioned Material, D. C. Sigee

Scanning Microscopy

Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular.

The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case …

Extraneous Background-Correction Program For Matrix Bound Multiple Point X-Ray Microanalysis, W. C. De Bruijn, M. P. C. Van Miert

Scanning Microscopy

A program is described that allows online determination of extraneous background in multiple point X-ray microanalytical matrices. The program is based upon the calculations of the extraneous background for the film (when present), the standard and the unknown by (100 sec.) point analysis. The program searches for a peak-free part of the spectrum in which the calculated value for the extraneous background is about equal to the value in this region of the spectrum (=b_e). Online the contents of this b_e-region is subtracted from an unmanipulated continuum region in the vicinity of the element present in …

Elemental Levels In Mast Cell Granules Differ In Sections From Normal And Diabetic Rats: An X-Ray Microanalysis Study, Marion D. Kendall

Scanning Microscopy

Mast cells around the thymus of rats stain red with alcian blue and safranin indicating that the mast cells are probably of the peritoneal (connective tissue) type. After the onset of streptozotocin induced diabetes some cells contain both red and blue granules and blue staining cells may appear.

X-ray microanalysis of frozen freeze-dried sections from diabetic male CSE Wistar rats showed electron dense granules to have similar amounts of S to normal rat mast cell granules but reduced levels of Na, Mg, P, Cl and K. Two cells also had electron lucent granules with very high levels of Na, Cl, …

Scanning Electron Microscopy, X-Ray Microanalysis And Immunohistochemistry On Worn Soft Contact Lenses, Piera Versura, M. C. Maltarello, Godfried M. Roomans, R. Caramazza, R. Laschi

Scanning Microscopy

The deposits accumulated on the surfaces of soft contact lenses are a cause of problems for the wearer of these lenses, as the deposits are never completely removed by the available washing solutions. Therefore it appears of interest to investigate the composition of these deposits.

In this paper we review the major findings in the literature and, in addition, present our personal experience.

We have studied new, continuously and daily worn soft contact lenses by scanning electron microscopy (SEM), X-ray microanalysis and immunohistochemistry. We have carefully evaluated preparative methods, and we can conclude that SEM and X-ray microanalysis are best …

Image Analysis And X-Ray Microanalysis In Cytochemistry, W. C. De Bruijn, H. K. Koerten, M. I. Cleton-Soeteman, C. J. G. Blok-Van Hoek

Scanning Microscopy

When cytochemical reaction products are homogeneously distributed within an organelle, point analyses suffice for the quantitative approach. However, quantitative analysis becomes tedious, when the elements in the reaction product are inhomogeneously distributed. Problems arise when elements from two reaction products have to be related to each other, or to endogenous cytological products (ferritin, haemosiderin, calcium, electron dense markers), either topographically or in concentration. When analyzing inhomogeneous/heteromorphical reaction product-containing organelles special attention has to be paid to measure and relate both volume and concentration. In this paper a relative simple structure (eosinophil granules) is chosen to demonstrate that the acquisition of …

Fictitious Calculi And Human Calculi With Foreign Nuclei, P.-T. Cheng, K. P. H. Pritzker, J. Richards, D. Holmyard

Scanning Microscopy

The correlative approach employing polarized light microscopy, x-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray microanalysis proves to be very useful in identifying fictitious calculi and genuine human calculi with foreign body nuclei. The common artifacts as reported in the literature and observed also by us were minerals, vegetable and plant seeds, cereals, sand grains and sea shell fragments.

Two interesting cases involving foreign body nuclei have been reported: one urinary calculus containing a piece of plastic-coated titanium foil in the center; one nasal calculus with a nut as a nucleus. …

X-Ray Microanalysis Of Cells In Suspension And The Application Of This Technique To The Study Of The Thymus Gland, A. Warley

Scanning Microscopy

Although X-ray microanalysis has become a well established technique in the study of tissues there are still relatively few papers reporting results from cells in culture. Our early investigations on freshly isolated murine thymocytes reported higher than expected concentrations of Na and Cl in these cells but subsequent studies have shown that these high concentrations are artefactual. Rat thymocytes that have been isolated and incubated for a short time to allow them to recover from the isolation procedure have lower concentrations of Na and Cl. Sections prepared from pellets of cells which have been concentrated by centrifugation in a microhaematocrit …

Studies On The Occurrence And Elemental Composition Of Bacteria In Freshwater Plankton, K. N. Booth, D. C. Sigee, E. Bellinger

Scanning Microscopy

The occurrence and cation content of bacteria in a eutrophic freshwater lake (Rostherne Mere, Cheshire, UK) were investigated over a one year sampling period in relation to cation changes in the lake surface water and phytoplankton.

Scanning electron microscope examination of trawl-net and filtered samples demonstrated bacterial association with Anabaena, Aphanizomenon and diatoms. Direct counts of associated and unassociated bacteria showed that increases in bacterial population relate to population decline of major algal constituents.

Spectrophotometric determination of selected cation levels in the lake water demonstrated wide fluctuations throughout the sampling period, with elevated levels of transition metals before and at …

Low Temperature Techniques In Biomedical Microanalysis, Romuald Wróblewski, Joanna Wroblewski, Godfried M. Roomans

Scanning Microscopy

Many diseases are associated with a change in the distribution of diffusible ions at the cell or tissue level. These diseases can profitably be studied by X-ray microanalysis. This technique for the study of ion distribution requires the use of cryoprepared specimens. Analysis at low or medium resolution can be carried out on thick or semi-thick cryosections, or on frozen-hydrated or freeze-dried embedded bulk samples. Such analyses are particularly useful in the initial stages of an investigation, or when many data from a large number of samples have to be acquired. Quantitative analysis is then usually carried out with the …

X-Ray Microanalysis Of Growth Cartilage After Rapid Freezing, Low Temperature Freeze Drying And Embedding In Resin, J. Appleton

Scanning Microscopy

This paper reviews the work undertaken on the X-ray microanalysis of growth cartilage particularly in relation to matrix calcification. Attention is focused on the methodology available to accurately localize and retain the elements of interest. A method is described which involves rapid freezing, low temperature freeze drying in a custom built device, and embedding in Spurr resin. The results show that little tissue damage occurs and that elements of physiological interest are accurately localized at the sub-cellular level. Where damage occurs to chondrocytes as a result of freezing, however, dense intra mitochondrial granules are seen suggesting a phase transformation takes …

Distinguishing Adult Pectinophora Scutigera (Holdaway) According To Larval Diet By X-Ray Microanalysis, R. A. Lewis, P. W. Walker

Scanning Microscopy

In an exploratory study using scanning electron microscope (SEM) based energy dispersive spectroscopy (EDS) of X-rays, differences were detected in the elemental compositions of adult Pectinophora scutigera raised on contrasting diets - cotton, Hibiscus tiliaceus and laboratory medium.

X-ray spectra were collected from the thorax and abdomen of 13 male and 13 female moths. X-ray yields are optimised by ashing the insects for 1 h at 400-600°C, and by operating the SEM at 25 kV.

Spectrum matching, element matching, discriminant analysis and principal components analysis were used to classify the specimens on the basis of diet with 54-100% success. Spectra …