scholarly journals Improvements in the silver-staining technique for nucleolar organizer regions (AgNOR).

1993 ◽  
Vol 41 (3) ◽  
pp. 439-445 ◽  
Author(s):  
L E Lindner
Keyword(s):  
Silver Staining ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Nucleolar Organizer Regions ◽  
Silver Stain ◽  
Oxidation Reduction ◽  
Background Staining ◽  
Silver Staining Technique ◽  
Selection Of ◽  
Nucleolar Function

The silver-staining technique for nucleolar organizer regions (AgNOR) of Ploton et al., as popularized by Crocker, is being widely used for evaluation of nucleolar function, especially in neoplasia. It suffers from limited reliability, background staining, precipitates, and fading of the sections. Factors were identified that affect these problems. The oxidation-reduction level and gelatin used are particularly important. An improved procedure is presented which incorporates pre-reduction of the sections, selection of an optimal gelatin, and post-treatment of the sections to produce a permanent preparation. It is compatible with many fixatives and with other stains used before or after the silver stain.

A simple silver-staining technique for detecting Bence Jones proteins in unconcentrated urine.

1987 ◽  
Vol 33 (4) ◽  
pp. 561-563 ◽  
Author(s):  
J M Sheat ◽  
M A Lorier
Keyword(s):  
Silver Staining ◽  
Clinical Laboratory ◽  
Staining Technique ◽  
Silver Stain ◽  
Concentration Step ◽  
Silver Staining Technique ◽  
Bence Jones Proteins

Abstract Detection of Bence Jones proteins in urine usually involves a concentration step, followed by electrophoresis and, if necessary, immunofixation. The time-consuming and expensive concentration step can be eliminated by use of the silver-stain technique described here. This procedure, routinely used for staining unconcentrated urine, is inexpensive, sensitive, and easily performed in a clinical laboratory. Bence Jones proteins can be detected in concentrations as low as 5 mg/L.

scholarly journals The Role of Argyrophilic Nucleolar Organizer Region (AgNOR) Study in Cytological Evaluation of Fluids, Especially for Detection of Malignancy

2012 ◽  
Vol 10 (1) ◽  
pp. 34-39 ◽  
Author(s):  
S Karki ◽  
A Jha ◽  
G Sayami
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Nucleolar Organizer Regions ◽  
Serous Effusion ◽  
Malignant Cells ◽  
Associated Proteins ◽  
Malignant Effusions

Background Serous effusion smears reported as “suspicious for malignancy” pose problems in clinical management. Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologic differential diagnosis between benign and malignant cells. Nucleolar organizer regions(NORs) are loops of DNA located in acrocentric chromosomes. These NORs are visualized by silver staining technique that recognizes these argyrophilia associated proteins which are increased in malignancy. Objective This study aimed to distinguish reactive mesothelial cells from malignant cells in serous effusions using these NORs. Methods A total of 174 serous effusions received at the Department of Pathology, TUTH, during a period of one year were included in the study. Smears were studied by conventional Papanicolaou and Giemsa stains. AgNOR counts, variation in size and dispersion of AgNOR dots in smears were graded and compared in malignant and non-malignant effusions. Results Mean AgNOR counts of 10.43±0.73 and 10.21±0.51 in malignant peritoneal and pleural effusions, respectively, were significantly (p<0.0001) greater as compared with counts of 2.12±0.54 and 2.11±0.54 in non-malignant effusions. The AgNORs were irregular in shape in malignant effusions whereas they were comparatively larger, single dots in benign effusions. AgNOR size and dispersion were of higher grade in significantly greater proportion of malignant as compared with non malignant effusions (p<0.0001). Of the cytologically suspicious samples, nine were in the malignant range and one was in the benign range. Conclusion AgNOR study appears to be clinically useful as an additional diagnostic tool for use in serous effusion when the cytologic diagnosis is difficult. KATHMANDU UNIVERSITY MEDICAL JOURNAL  VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 44-47 DOI: http://dx.doi.org/10.3126/kumj.v10i1.6913

Sequential silver staining and in situ hybridization reveal a direct association between rDNA levels and the expression of homologous nucleolar organizing regions: a hypothesis for NOR structure and function

1998 ◽  
Vol 111 (10) ◽  
pp. 1433-1439
Author(s):  
F. Zurita ◽  
R. Jimenez ◽  
M. Burgos ◽  
R.D. de la Guardia
Keyword(s):  
Transcription Factors ◽  
In Situ Hybridization ◽  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer ◽  
Interindividual Variation ◽  
Nucleolar Organizer Regions ◽  
Single Pair ◽  
Ribosomal Cistrons

We have developed a procedure for sequential silver staining and in situ hybridization to analyze the relationship between the amount of rDNA present in nucleolar organizer regions, as estimated by in situ hybridization, and their level of expression, as estimated by the silver signal. For simplicity we used cells from the insectivorous mole Talpa occidentalis, which have a single pair of nucleolar organizer regions in chromosome pair 3. The relative content of ribosomal cistrons was also related to the hierarchy of activation of the nucleolar organizer regions present in this chromosomal pair. Statistical analyses demonstrated that both the relative level of expression and the activation hierarchy depended mainly on the number of ribosomal cistrons in nucleolar organizer regions. We propose a functional two-step hypothesis, which is consistent with most known data concerning interchromosomal, intercellular and interindividual variation in a number of plant and animal species, including Talpa occidentalis. In step one, the first available transcription factors bind randomly to the ribosomal promoters, such that larger nucleolar organizer regions are more likely to recruit them. In the second step the remaining transcription factors are recruited in a cooperative way, thus completing activation of one nucleolar organizer region, before the next one becomes active.

Number of Nucleoli and Nucleolar Organizer Regions per Nucleus and Nucleolus — Prognostic Value in Canine Mammary Tumors

1996 ◽  
Vol 33 (5) ◽  
pp. 527-532 ◽  
Author(s):  
M. BratuliĆ ◽  
Ž GrabareviĆ ◽  
B. ArtukoviĆ ◽  
D. Capak
Keyword(s):  
Malignant Tumors ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Mammary Tumors ◽  
World Health ◽  
Nucleolar Organizer Regions ◽  
Canine Mammary Tumors ◽  
Significant Difference

Twenty-eight canine mammary tumors were evaluated for histopathologic classification as recommended by the World Health Organization and silver-binding nucleolar organizer region (AgNOR) and nucleolus counts. Samples of surgically excised tumors and tumors taken at necropsy were fixed in neutral formalin, embedded in paraffin, and cut into 1-3-μm-thick sections. Two sections were taken from each tumor: one was stained with hematoxylin and eosin and the other was treated with the silver staining technique for the demonstration of AgNORs. After histopathologic classification, the number of nucleoli and the number of AgNORs/nucleus and AgNORs/nucleolus were determined. Statistical analysis (Student's t-test) showed a significant difference in the mean number of nucleoli ( P < 0.005), mean number of AgNORs/nucleolus ( P < 0.001), and mean number of AgNORs/nucleus ( P < 0.005) between benign and malignant canine mammary tumors. There was no significant differences between metastatic and nonmetastatic malignant tumors.

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