Reproducibility of Probing Depth Measurements Using a Constant-Force Electronic Probe: Analysis of Inter- and Intraexaminer Variability

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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The use of a Bent Grid to Improve the take-Off Angle for Electron Probe Analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091780 ◽

1976 ◽

Vol 34 ◽

pp. 360-361

Author(s):

Delbert E. Philpott ◽

David Leaffer

Keyword(s):

Quantitative Analysis ◽

Tilt Angle ◽

Count Rate ◽

Electron Probe ◽

Open Area ◽

Electron Probe Analysis ◽

Background Ratio ◽

Probe Analysis

There are certain advantages for electron probe analysis if the sample can be tilted directly towards the detector. The count rate is higher, it optimizes the geometry since only one angle need be taken into account for quantitative analysis and the signal to background ratio is improved. The need for less tilt angle may be an advantage because the grid bars are not moved quite as close to each other, leaving a little more open area for observation. Our present detector (EDAX) and microscope (Philips 300) combination precludes moving the detector behind the microscope where it would point directly at the grid. Therefore, the angle of the specimen was changed in order to optimize the geometry between the specimen and the detector.

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Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091652 ◽

1976 ◽

Vol 34 ◽

pp. 334-335 ◽

Cited By ~ 1

Author(s):

Avril V. Somlyo ◽

H. Shuman ◽

A.P. Somlyo

Keyword(s):

Smooth Muscle ◽

Electron Probe ◽

Preliminary Report ◽

Cell Damage ◽

Electron Probe Analysis ◽

Perinuclear Space ◽

Probe Analysis ◽

High K ◽

Low K ◽

Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

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