Localization of cations by pyroantimonate. II. Electron probe microanalysis of calcium and sodium in skeletal muscle of mouse.

A new formulation of the pyroantimonate (PA) method for localization of calcium and sodium is proposed and evaluated in mouse skeletal muscle. This study, performed at the ultrastructural level by means of transmission electron microscopy (TEM) and electron probe microanalysis (EPMA), completes a previous work done at the optical level with analytical ion microscopy (AIM), which enabled us to define the appropriate composition of fixatives. In our present experiments, calcium and sodium were shown localized in various cell structures, e.g., T-tubules, glycogen, granules, nuclei. For AIM, the best fixatives were characterized by PA supersaturation, which resulted in smaller crystals and a high rate of penetration in the presence of paraformaldehyde and either phenol or collidine. Contrary to the findings at the optical level, collidine did not give satisfactory results at the ultrastructural level. The method of floating sections on the microtome trough was an important cause of cation displacement. We found that alkalinization of the floating medium significantly decreased ion loss. The technique also provided an indication of the form of these elements: free or easily liberated cations were precipitated into coarse PA deposits; electron-positive chelates were "stained" by PA; neutral chelates were not stained, but some of them could be detected by EPMA. This PA method should make possible more precise localization of cellular calcium, such as in glycogen metabolism, and perhaps detection of movements of cytoplasmic calcium and sodium.

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Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054595 ◽

1982 ◽

Vol 40 ◽

pp. 402-403 ◽

Cited By ~ 1

Author(s):

Claude Lechene

Keyword(s):

Liquid Nitrogen ◽

Electron Probe Microanalysis ◽

Electron Probe ◽

Cultured Cells ◽

Liquid Nitrogen Temperature ◽

Elemental Content ◽

Isolated Cells ◽

Renal Tubular Cells ◽

Diamond Saw ◽

Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

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Electron Probe Analysis of Muscle

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054583 ◽

1982 ◽

Vol 40 ◽

pp. 398-401

Author(s):

A. V. Somlyo ◽

H. Shuman ◽

A. P. Somlyo

Keyword(s):

Skeletal Muscle ◽

Smooth Muscle ◽

Sarcoplasmic Reticulum ◽

Resting State ◽

Binding Sites ◽

Electron Probe ◽

Frog Skeletal Muscle ◽

Electron Probe Analysis ◽

Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

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Analysis of completed commercial semiconductors using EPMA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164970 ◽

1996 ◽

Vol 54 ◽

pp. 502-503

Author(s):

R. Packwood ◽

M.W. Phaneuf ◽

V. Weatherall ◽

I. Bassignana

Keyword(s):

Electron Probe Microanalysis ◽

Electron Probe ◽

Semiconductor Industry ◽

Detection Limits ◽

High Technology ◽

Depth Resolution ◽

Analytical Instruments ◽

Wide Range ◽

Numerous Element ◽

Choice Method

The development of specialized analytical instruments such as the SIMS, XPS, ISS etc., all with truly incredible abilities in certain areas, has given rise to the notion that electron probe microanalysis (EPMA) is an old fashioned and rather inadequate technique, and one that is of little or no use in such high technology fields as the semiconductor industry. Whilst it is true that the microprobe does not possess parts-per-billion sensitivity (ppb) or monolayer depth resolution it is also true that many times these extremes of performance are not essential and that a few tens of parts-per-million (ppm) and a few tens of nanometers depth resolution is all that is required. In fact, the microprobe may well be the second choice method for a wide range of analytical problems and even the method of choice for a few.The literature is replete with remarks that suggest the writer is confusing an SEM-EDXS combination with an instrument such as the Cameca SX-50. Even where this confusion does not exist, the literature discusses microprobe detection limits that are seldom stated to be as low as 100 ppm, whereas there are numerous element combinations for which 10-20 ppm is routinely attainable.

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