scholarly journals Sensitivity in electron microscope autoradiography for calcium-45.

1980 ◽  
Vol 28 (1) ◽  
pp. 40-44 ◽  
Author(s):  
W V Harris ◽  
M M Salpeter
Keyword(s):  
Electron Microscope ◽  
Radiation Dose ◽  
Double Layers ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography

The sensitivity of Ilford L4 emulsion to 45Ca was determined for electron microscope autoradiographic conditions. Sensitivity values were obtained for monolayers and double layers of emulsion in combination with various developing procedures. The dependence of sensitivity upon radiation dose was determined. All results are compared to previously calibrated isotopes.

scholarly journals SENSITIVITY IN ELECTRON MICROSCOPE AUTORADIOGRAPHY FOR 125I

1974 ◽  
Vol 22 (2) ◽  
pp. 80-87 ◽  
Author(s):  
HELEN C. FERTUCK ◽  
MIRIAM M. SALPETER
Keyword(s):  
Heavy Metal ◽  
Electron Microscope ◽  
Radiation Dose ◽  
Dose Dependence ◽  
Specimen Thickness ◽  
Section Thickness ◽  
Electron Microscope Autoradiography ◽  
Absorption Studies ◽  
Microscope Autoradiography ◽  
Better Than

Sensitivity in electron microscope autoradiography was determined for 125I. Values are given using Ilford L4 and Kodak NTE emulsions combined with different developers. The extent of self-absorption as a function of section thickness and heavy metal staining and the effect of radiation dose (dose dependence) were assessed. It was found that the over-all efficiency for 125I was better than that for tritium and that, as is the case with tritium, there is a distinct "dose dependence" especially when Microdol X is the developer. Self-absorption studies indicate that self-absorption is increased by about 15% when the specimen thickness is increased from 300 to 1000 Å. An increase of under 15% is also introduced by heavy metal staining of sections in this thickness range.

scholarly journals ERRATUM

1972 ◽  
Vol 20 (11) ◽  
pp. 967-967
Keyword(s):  
Electron Microscope ◽  
Radiation Dose ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography

In the paper by Salpeter and Szabo entitled "Sensitivity in Electron Microscope Autoradiography. I. The Effect of Radiation Dose," which appeared in the June issue of the Journal (Vol. 20, pp. 425-434, 1972), the lines 28 and 29 of column 2 on page 427 should read, "2. In a second method, sections of tritiated methacrylate (10 mC/g or 400 µC/g) were used...."

scholarly journals SENSITIVITY IN ELECTRON MICROSCOPE AUTORADIOGRAPHY I. THE EFFECT OF RADIATION DOSE

1972 ◽  
Vol 20 (6) ◽  
pp. 425-434 ◽  
Author(s):  
MIRIAM M. SALPETER ◽  
MARIA SZABO
Keyword(s):  
Ascorbic Acid ◽  
Electron Microscope ◽  
Radiation Dose ◽  
Surface Area ◽  
Test Specimen ◽  
Dose Dependence ◽  
Unit Surface Area ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
Unit Surface

Sensitivity in electron microscope autoradiography using Ilford L4 emulsion was shown to be affected by radiation dose ( i.e., number of decays in test specimen per unit surface area). The sensitivity tended to be higher with lower doses. This dose dependence was most marked with Microdol X and least with gold latensification-Elon ascorbic acid development. Possible consequences for quantitation in electron microscope autoradiography are discussed.

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

Synthesis and Localization of Sulphated Mucopolysaccharide in Megakaryocytes and Platelets of the Rat, An Analysis by Electron-Microscope Autoradiography

1972 ◽  
Vol 10 (3) ◽  
pp. 705-717
Author(s):  
G. G. MacPHERSON
Keyword(s):  
Electron Microscope ◽  
Golgi Apparatus ◽  
Blood Platelets ◽  
Total Activity ◽  
Electron Microscope Autoradiography ◽  
Dense Granules ◽  
Level Of Activity ◽  
Microscope Autoradiography ◽  
Almost All

Electron-microscope autoradiography has been used to investigate the synthesis and localization of sulphated mucopolysaccharide in megakaryocytes and blood platelets. Following 10-min incubation of bone marrow with 35S-sulpahte in vitro the majority of the activity in megakaryocytes was associated with the Golgi apparatus, but a substantial proportion was associated with other cytoplasmic organelles, suggesting either rapid transport or sulphation of mucopolysaccharide outside the Golgi apparatus. Three hours after the intravenous injection of 35SO4 only a small proportion of the total activity was associated with the Golgi apparatus, most being associated with demarcation membranes and dense granules, while 12 h after injection almost all the activity was associated with demarcation membranes and granules. A rising proportion of activity localized solely on the demarcation membranes suggested that they may possess some activity of their own. Autoradiographs of blood platelets prepared 72 h after the injection of 35SO4 were analysed. It was shown that most of the activity was associated with the α-granules, but there was strong evidence that the platelet membrane possessed a low level of activity.

Timing of nucleolar DNA replication in Amoeba proteus

1976 ◽  
Vol 22 (3) ◽  
pp. 521-530
Author(s):  
I. Minassian ◽  
L.G. Bell
Keyword(s):  
Electron Microscope ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Central Region ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
G2 Phase

Light- and electron-microscope autoradiography have been used to follow the incorporation of [3H]thymidine at different stages during the interphase of synchronously growing populations of Amoeba proteus. Two main patterns were found for tritiated thymidine incorporation, i.e. DNA synthesis. The major incorporation was in the central region of the nucleus, but a lesser degree of incorporation occurred in the nucleolar region. The bulk of this nucleolar DNA was found to be late replicating, i.e. it replicated during the G2 phase.

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