scholarly journals A combined AgNOR-Feulgen staining technique.

1990 ◽  
Vol 38 (11) ◽  
pp. 1591-1597 ◽  
Author(s):  
J Foucrier ◽  
J P Rigaut ◽  
D Pechinot
Keyword(s):  
Transcriptional Activity ◽  
Staining Method ◽  
Staining Technique ◽  
Nucleolus Organizer ◽  
Optimal Conditions ◽  
Feulgen Staining ◽  
Rdna Genes ◽  
Nucleolus Organizer Regions ◽  
Agnor Staining

We describe a new staining technique (H-Ag-S) which allows observation and counting of active nucleolus organizer regions (NORs) and evaluation of the amount of DNA in the same cell nucleus. The procedure consists of combining a modified AgNOR staining method with the Feulgen reaction. A sequential procedure is proposed, based on the determination of optimal staining conditions. The technique, which was designed to allow studies of correlations between the transcriptional activity of rDNA genes and the cell ploidy, was primarily developed for rat liver smears. It should be applicable to most biological preparations, but the optimal conditions might be variable.

Surface Ultrastructure of Gram (−) Bacteria: II. Determination of the Gram Reaction in Antartic Soil Bacteria by Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 178-179
Author(s):  
I. L. Uydess ◽  
Wolf Vishniac
Keyword(s):  
Staining Method ◽  
Staining Technique ◽  
Culture Conditions ◽  
Gram Stain ◽  
Accurate Identification ◽  
Surface Ultrastructure ◽  
Antarctic Soils ◽  
Cell Age ◽  
Pure Cultures

A modified negative staining technique (“OTPT”) has been described in the study of the surface topography of bacteria. This technique is useful in the rapid and accurate identification and discrimination of the Gram reaction of unknown bacteria under circumstances unfavorable to the direct application of the Gram stain. Cells of a particular genus exhibit the same basic topographical features independent of cell age, culture conditions or other cellular parameters.Several pure cultures of unclassified bacteria isolated from Antarctic soils were prepared by the OTPT staining method. Although initial attempts employing the Gram stain were often inconclusive, this technique allowed a positive identification of all samples. Two organisms were chosen for more detailed study.

scholarly journals Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs)

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 971
Author(s):  
Hirohisa Hirai
Keyword(s):  
Transcriptional Activity ◽  
Nucleolus Organizer ◽  
Nucleolus Organizer Regions ◽  
Dispersion Systems ◽  
Rdna Loci ◽  
Silver Nitrate Staining ◽  
Staining Methods ◽  
Acrocentric Chromosomes ◽  
Reciprocal Associations

The nucleolus organizer regions (NORs) demonstrate differences in genomic dispersion and transcriptional activity among all organisms. I postulate that such differences stem from distinct genomic structures and their interactions from chromosome observations using fluorescence in situ hybridization and silver nitrate staining methods. Examples in primates and Australian bulldog ants indicate that chromosomal features indeed play a significant role in determining the properties of NORs. In primates, rDNA arrays that are located on the short arm of acrocentrics frequently form reciprocal associations (“affinity”), but they lack such associations (“non-affinity”) with other repeat arrays—a binary molecular effect. These “rules” of affinity vs. non-affinity are extrapolated from the chromosomal configurations of meiotic prophase. In bulldog ants, genomic dispersions of rDNA loci expand much more widely following an increase in the number of acrocentric chromosomes formed by centric fission. Affinity appears to be a significantly greater force: associations likely form among rDNA and heterochromatin arrays of acrocentrics—thus, more acrocentrics bring about more rDNA loci. The specific interactions among NOR-related genome structures remain unclear and require further investigation. Here, I propose that there are limited and non-limited genomic dispersion systems that result from genomic affinity rules, inducing specific chromosomal configurations that are related to NORs.

scholarly journals Technique and Feasibility of a Dual Staining Method for Estrogen Receptors and AgNORs

2000 ◽  
Vol 20 (4) ◽  
pp. 151-154 ◽  
Author(s):  
Lukas Günther ◽  
Peter Hufnagl
Keyword(s):  
Estrogen Receptors ◽  
Staining Method ◽  
Nucleolus Organizer ◽  
Reciprocal Effects ◽  
Image Analysis System ◽  
Breast Cancers ◽  
Specific Staining ◽  
Nucleolus Organizer Regions ◽  
Analysis System ◽  
Dual Staining

A new staining method for dual demonstration of Estrogen receptors (ER) and argyrophilc Nucleolus‐Organizer Regions (AgNORs) was developed. To rule out possible reciprocal effects, serial slides of 10 invasive ductale breast cancers were stained with either the single staining method or the simultaneous ER/AgNOR‐staining method and investigated comparatively. By measuring the slides with the image analysis system AMBA, reciprocal effects could be excluded. It was proven that dual staining of both markers results in a reproducible and specific staining result. We concluded that it is justified to measure AgNORs in immunohistochemically stained cells.

Evaluation of Proliferative Activity in Oral Squamous Cell Carcinoma by the AgNOR Staining Method

Odonto ◽  
2011 ◽  
Vol 19 (38) ◽  
pp. 115-121
Author(s):  
S.O. Silva ◽  
K.P. Gatto ◽  
J.P. De Carli ◽  
P.H.C. Souza ◽  
C.S. Busin
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Proliferative Activity ◽  
Staining Method ◽  
Agnor Staining

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

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