Experiments on the Mechanism of Silver Staining

1955 ◽  
Vol s3-96 (35) ◽  
pp. 301-315
Author(s):  
A. PETERS

The quantitative aspects of silver staining of sections have been investigated with radioactive silver (Ag111). The concentrations of reducible silver, developed silver, and silver nuclei in the sections were determined, but it is doubtful if the values obtained for silver nuclei are significant. All three forms of silver increased with pH, time, and the concentration of silver in the impregnating solution. Temperature of impregnation had little effect on the uptake of reducible silver, but increased the developed silver, presumably by increasing the silver nuclei. An increase in the temperature of a hydroquinone-sulphite developer increased the amount of reducible silver reduced by the developer. The deposition of silver by a glycine physical developer was shown to follow a curve which was reasonably consistent with the assumption of a typical autocatalytic reaction. The uptake of silver by non-nervous tissues provided evidence that the process is not specific for nerves; the final specificity of staining is determined during development. The quantitative results are consistent with the hypothesis that the histidine in the sections is responsible for the combination of reducible silver.

1955 ◽  
Vol s3-96 (33) ◽  
pp. 103-115
Author(s):  
A. PETERS

The effect of a series of photographic developers on the final silver-staining picture has been investigated. Ten common developers were used, but of these only hydroquinone, chloroquinol, pyrogallol, and p-aminophenol, were found to be of general use. The other developers were either so weak in their action that the final staining was light and incomplete, or so powerful that a differentiated nerve staining was not produced. For silver staining to be effected nuclei of reduced silver should be present in the section. These nuclei act as centres for the deposition of additional silver reduced by the developer; the additional silver may either be derived from that combined with the sections during impregnation or from the developing solution itself. Whether or ot the additional silver is deposited in such a way as to produce differentiated nerve staining depends on the properties of the developer and on the composition of the developing solution. The redox- and ‘bromide’-potentials, the sulphite and hydrogen n concentrations in the developing solution, and the protective action of the tissue components of the section all play a part in determining the final staining picture. A new glycine-containing physical developer and a gold thiocyanate physical developer are described.


1986 ◽  
Vol 34 (7) ◽  
pp. 935-939 ◽  
Author(s):  
M De Waele ◽  
J De Mey ◽  
W Renmans ◽  
C Labeur ◽  
P Reynaert ◽  
...  

An immunogold-silver staining technique for detection of cell-surface antigens in cell suspensions was developed. Leukocyte cell suspensions were first incubated with monoclonal antibodies directed against cell-surface antigens and then with colloidal gold-labeled goat anti-mouse antibodies. Cytocentrifuge preparations of the cell suspensions were immersed in a physical developer containing silver lactate and hydroquinone as reducing substance. The preparations were then counterstained and mounted. In light microscopy, cells reacting with the monoclonal antibodies showed dark granules on their surface membrane. An optimal morphology, as revealed by a May-Grünwald-Giemsa counterstain, permitted accurate cell identification. The labeling was influenced by the gold particle diameter and the concentration of the gold reagents, by the duration of incubation in the physical developer, and by the composition and temperature of this medium. The T-cell subsets enumerated with this method in the peripheral blood of normal adults were identical to those found with other methods. The sensitivity of the technique was comparable with that of immunofluorescence microscopy. This immunogold-silver staining procedure proved to be a reliable tool for detection of cell-surface antigens in light microscopy.


1955 ◽  
Vol s3-96 (35) ◽  
pp. 323-328
Author(s):  
A. PETERS

A method of silver staining for paraffin sections has been described. Sections should be fixed in either Nonidez fixative, 4% formaldehyde, or 4% formaldehyde saturated with mercuric chloride. The sections are impregnated for 16 hours in 1/20,000 silver nitrate at pH 8 or 9 and developed in a glycine physical developer after the reducible silver has been removed with a 2% solution of sodium sulphite. The effect of pH on impregnation has been described. A spectrum of staining was obtained in which nerve fibres began to stain appreciably at pH 7, cell nuclei at pH 8, cell cytoplasm at pH 9, and connective tissue at higher pH values. Therefore, impregnation should be carried out at pH 8 to obtain a good staining of nerve fibres and at pH 9 if some staining of cell bodies is also required.


Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.


Author(s):  
C. Colliex ◽  
P. Trebbia

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.


Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.


Author(s):  
Robyn Rufner ◽  
Gerhard W. Hacker ◽  
Michele Forte ◽  
Nancyleigh E. Carson ◽  
Cristina Xenachis ◽  
...  

The use of immunogold-silver staining (IGSS) to enhance label penetration and Localization for immunocytochemistry or in situ hybridization utilizing a variety of metallic salts has been documented. In this morphological study, the effects of silver acetate, silver lactate and silver nitrate were evaluated for immunogold-labeling of a trial natriuretic peptides (ANP) in rat right atria.Eight Wistar Kyoto retired breeders were sedated with pentobarbital, perfused with either 4% paraformaldehyde (LM) or Karnovsky's fixative (EM), and right atria were dissected, processed, embedded in paraffin or epon, respectively and sectioned according to conventional methods. For light microscopy, an indirect IGSS method according to Hacker (3) was performed. Paraffin sections on glass slides were washed in ddH2O, immersed in Lugol's iodine, washed in ddH2O and treated with 2.5% aqueous sodium thiosulfate for 20 sec. After additional washes in ddH2O and TBS-0.1% fish gelatin, 10% normal goat serum (PBS with 1% BSA) was applied for 20 min before an overnight incubation at 4°C with a polyclonal α-ANP primary antibody (Peninsula Labs, 1:1000 in TBS/BSA).


2019 ◽  
Vol 28 (3) ◽  
pp. 660-672
Author(s):  
Suzanne H. Kimball ◽  
Toby Hamilton ◽  
Erin Benear ◽  
Jonathan Baldwin

Purpose The purpose of this study was to evaluate the emotional tone and verbal behavior of social media users who self-identified as having tinnitus and/or hyperacusis that caused self-described negative consequences on daily life or health. Research Design and Method An explanatory mixed-methods design was utilized. Two hundred “initial” and 200 “reply” Facebook posts were collected from members of a tinnitus group and a hyperacusis group. Data were analyzed via the LIWC 2015 software program and compared to typical bloggers. As this was an explanatory mixed-methods study, we used qualitative thematic analyses to explain, interpret, and illustrate the quantitative results. Results Overall, quantitative results indicated lower overall emotional tone for all categories (tinnitus and hyperacusis, initial and reply), which was mostly influenced by higher negative emotion. Higher levels of authenticity or truth were found in the hyperacusis sample but not in the tinnitus sample. Lower levels of clout (social standing) were indicated in all groups, and a lower level of analytical thinking style (concepts and complex categories rather than narratives) was found in the hyperacusis sample. Additional analysis of the language indicated higher levels of sadness and anxiety in all groups and lower levels of anger, particularly for initial replies. These data support prior findings indicating higher levels of anxiety and depression in this patient population based on the actual words in blog posts and not from self-report questionnaires. Qualitative results identified 3 major themes from both the tinnitus and hyperacusis texts: suffering, negative emotional tone, and coping strategies. Conclusions Results from this study suggest support for the predominant clinical view that patients with tinnitus and hyperacusis have higher levels of anxiety and depression than the general population. The extent of the suffering described and patterns of coping strategies suggest clinical practice patterns and the need for research in implementing improved practice plans.


1976 ◽  
Vol 36 (02) ◽  
pp. 430-440 ◽  
Author(s):  
A Marmur ◽  
E Ruckenstein ◽  
S. R Rakower

SummaryA model is suggested which assumes that the rate of deposition of cells is determined both by hydrodynamic factors and by Brownian motion over the potential barrier caused by London and double-layer forces in the immediate vicinity of the deposition surface. The height of the barrier in the potential energy of interaction between blood cells and various surfaces is analyzed in relation to the physical properties of the cells, surfaces, and solutions. Based on this analysis, the adhesion of platelets to injured blood vessel walls and to non-biologic materials, the lack of adhesion of red blood cells under the same conditions, the mechanism of ADP induced aggregation and the interaction with blood flow are explained. The qualitative predictions of the model are substantiated by available experimental information. Quantitative results are presented in terms of a time constant, which typifies a period of contact with a surface, during which appreciable deposition occurs.


1991 ◽  
Vol 65 (04) ◽  
pp. 360-363 ◽  
Author(s):  
P Han ◽  
K P Fung ◽  
U Rahdakrishnan

SummaryCoagulation serine proteases can be measured with either a chromogenic substrate assay or a clotting assay using deficient plasmas. It is a concern whether both assays give similar quantitative results, in particular in plasma obtained fiom patients on long term warfarin therapy. If these two assay methods were interchangeable, then the chromogenic substrate assay has the advantages of precision as well as laboratory automation. We used the intraclass correlation coefficient (r1) to assess the agreement between the two methods in measuring factor X and protein C levels in warfarinised plasma. The results indicate that the extent and pattern of agreement of the two methods for the measurement of the two variables in warfarinised plasma are poor, despite high Pearson product moment coefficients of correlation.


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