SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The silver staining techniques was used to study two cases of ring chromosomes (ring chromosome 15 and ring chromosome 22) and two cases of small extra chromosomes. This technique allows identification of the breakpoints and provides some information about the origin of small extra chromosomes.
RAPD analysis was performed between a near-isogenic line (NIL) Yr5/6 x Avocet S carrying the resistance gene Yr5 against wheat stripe rust and its susceptible parent Avocet S, using the Yr5 gene donor parent Triticum spelta album as control. Amplified DNA fragments were separated on 4% denaturing PAGE (polyacrylamide gel electrophoresis) and displayed by silver staining. Fifty to 100 bands were detected, 5 folds more than those revealed on agarose gels. A total of 240 random primers were screened, and 23 reproducible polymorphic DNA fragments were found, out of which 6 polymorphic bands appeared to be linked to Yr5 gene. Genetic linkage was tested on 121 segregating F2 plants derived from a cross between Avocet S and Yr5/6 x Avocet S. It was showed that the polymorphic DNA fragment S1320(207) was completely linked to Yr5 gene, and S1348(363) closely linked to Yr5 gene. The results suggested that using denaturing PAGE-silver staining could increase the level of DNA polymorphisms detected in wheat and also improve the repeatability of RAPD analysis.
A simple, sensitive silver staining method for sodium dodecyl sulfate polyacrylamide gel electrophoresis has been developed which yields high resolution of proteins with a transparent background. The method includes the incorporation of a water wash after a short fixation step in ethanol/ acetic acid and prior to glutaraldehyde cross-linking, which appears to be necessary for the high resolution staining of protein bands and the low background staining.
Unconcentrated cerebrospinal fluid (CSF) and corresponding serum from 30 patients with multiple sclerosis (MS), 30 with other neurological disease and 30 controls suffering from tension headache or psychoneurosis, were examined for oligoclonal IgG bands by initial separation employing agarose isoelectric focusing (AIF) followed by a modified procedure of immunofixation with monospecific antiserum and silver staining. This method is specific for demonstration of IgG and has a limit for detection of 0.4 microgram of IgG. Comparing the results with those obtained by AIF followed by capillary blotting to nitrocellulose membrane, double antibody peroxidase labeling and avidin-biotin amplification, both methods revealed similar frequencies of positive findings for oligoclonal IgG bands in the three patient groups. AIF followed by antiserum immunofixation and silver staining is a simple, sensitive and specific method for detection of oligoclonal IgG in unconcentrated CSF.
Three ultrasensitive protein silver-staining methods have been compared with respect to the detection of tRNA in polyacrylamide gels. The method of Sammons (D. W. Sammons, L.D. Adams, and E.E. Nishizawa (1981) Electrophoresis 2, 135-141) has been shown to have remarkable sensitivity, with a detection limit of 0.3 ng tRNA/mm2, allowing the two-dimensional fractionation of submicrogram amounts of bulk tRNA. The application of this technique to developmental and differentiation problems and other areas where the amounts of nonradioactive tRNA available are limited is anticipated.
We describe a new immunoassay which combines an immunosorbent assay, immunogold silver staining and epipolarization microscopy. Our new assay procedure features multiple samples on a single microscope slide, and high sensitivity of epipolarization microscope for detection of silver-enhanced colloidal gold as a final immunoassay product. We call the new immunoassay "on slide immunogold assay" (OSIGA). This new method uses biotinylated antibody and streptavidin-gold reaction with silver enhancement technique. With OSIGA it is possible to investigate 30 samples on a single microscopic slide. Our preliminary studies used 10-20 microliter samples and detected nanogram quantities of a standardized protein solution. Unlike enzyme linked immunosorbent assay (ELISA), which has a limited time for reading the final color products, the OSIGA specimens can be dried or resin mounted for longer storage and future reference.
Two-dimensional gel electrophoresis (2-DE) remains the method of choice for the Separation of protein mixtures whilst mass spectrometry (MS) is rapidly becoming the premier tool for protein identification. When combined, 2-DE and MS form the current operating paradigm for classical proteomics. One of the key challenges of proteome research is that of detecting and identifying all of the elements (proteins) of a proteome. Silver staining and radiolabelling, e.g. with 35S-methionine ([35S]-met), represent two sensitive methods used to visualise many of the constitutive and synthesised elements of a proteome, respectively. The latter method allows a very low total protein loading on a two-dimensional (2-D) gel and challenges protein identification using current MS-based technology. Therefore, it is necessary to refer to and locate a radiolabelled spot's cognate on a preparatively loaded stained gel, or Western blot, and use that protein spot for identification. Unfortunately, the images of autoradiographs and preparative gels or blots, even of the same sample, often do not correspond making it difficult to accurately locate and select spots of interest by visual comparison. We have established a technique that permits the unambiguous localisation of radiolabelled proteins on the same silver stained 2-D gel. Protein identification of superimposed spots is described by peptide mass fingerprinting and database searching using matrix-assisted laser desorption/ionization-time of flight mass spectrometry and by peptide sequencing using tandem MS by hybrid quadrupole/orthogonal acceleration time of flight MS (Q-TOF).
We have applied nucleolar organizer region (NOR) silver staining to the promyelocytic leukemia cell line HL-60, before and after dimethylsulfoxide (DMSO) mediated differentiation. The results demonstrated a gradual suppression of rDNA transcription during terminal maturation of these bone-marrow-derived cells and support our hypothesis that there are characteristic NOR staining profiles for different bone marrow cell types.
BACKGROUND: The value of nucleolar organizer regions (NOR) visualized by silver staining (AgNOR) for the histologic differentiation, pathologic staging, and estimation of growth rate was assessed by the investigation of paraffin sections from 58 lung adenocarcinomas. AgNOR consist of NOR-associated proteins, and the number of AgNOR might be related to proliferative activity. METHODS: In lung adenocarcinoma, the growth rate can be measured by means of chest radiographs. Using this technique, the authors studied the correlation between the mean number of AgNOR and growth rate. RESULTS: The mean number of AgNOR ranged from 1.8 to 6.3 (mean +/- standard deviation, 4.0 +/- 0.8). Neither the degree of histologic differentiation nor the pathologic staging was related to the AgNOR count. The tumor growth rate was estimated on the basis of the doubling time in the chest radiographs of 13 patients. The doubling time ranged from 80 to 760 days. There was a high inverse correlation between the AgNOR count and the doubling time (r = -0.910; P less than 0.001). CONCLUSIONS: Thus, it appears to be possible to use the mean number of AgNOR as an index of proliferative activity.
The quantification of proteins in silver-stained electrophoresis gels has been limited by the differences in "stainability" of different proteins. Despite efforts by many researchers, the precise basis of the reaction between silver reagents and polypeptides is still unclear, and, depending on the formulation, may even differ. We have tested the hypothesis that differences in stainability among proteins can be attributed to differences in di- or tripeptide composition. The results indicate that some order of protein structure other than short peptides accounts for the staining differences observed.
Using a combination of silver-staining and light microscopic techniques on human male meiotic preparations, it is feasible to study the morphology and behavior of both autosomal synaptonemal complexes and sex chromosome axes. During leptotene and early zygotene, the X and Y chromosomes are separate; their axes appearing as thin, filamentous structures. During late zygotene/early pachytene, the sex chromosomes come close to each other and a distinct sex vesicle is formed. We confirm existence of a short synaptonemal complex between the terminal ends of the X and Y chromosomes. In our preparations, a number of accessory structures can be seen along the axes of the sex chromosomes. These structures appear to be similar in morphology to those previously observed in several other mammalian species.
Although prenatal diagnosis has reduced the number of beta-thalassaemia births, pregnancy termination is still unacceptable for many couples. Preimplantation genetic diagnosis carried out on the third day after in-vitro fertilization offers an alternative. Here we describe the detection of selected beta-thalassaemia mutations in intron I at the single cell level by the application of nested polymerase chain reaction (PCR) and silver stained single strand conformation polymorphism (SSCP) analysis. A total of 294 single somatic cells of different types was amplified with 96% success and all tested mutations in homozygous and heterozygous form were identified correctly. None of the heterozygous or compound heterozygous samples showed any allele-specific amplification failure after the beta-globin gene amplification from single cells. To assess the efficiency of nested PCR on single blastomeres prior to clinical application, 10 single blastomeres were amplified and gave the expected normal pattern when analysed by SSCP. The main advantage of SSCP, particularly for preimplantation diagnosis, is that it allows the direct visualization of each allele and provides a simple means of assessing allele-specific amplification failure. Our results show that the combination of nested PCR and automated silver stained SSCP analysis offers exceptional resolution, accuracy and speed which are essential for preimplantation diagnosis.
An ultrasensitive method using a urea-silver staining procedure to detect trace quantities of proteins in polyacrylamide gels (PAGE) is described. This technique is sensitive enough to detect picogram quantities of proteins resolved on sodium dodecyl sulfate-polyacrylamide gels. The major advantages of our method are that it provides a clear background and it is more sensitive than other techniques allowing it to substitute for radioisotopic techniques in some cases.
A technique for distinguishing nucleolar components by light microscopy is described. Silver staining is used for localizing nuceolar-organizing regions. A new RNA-specific fluorochrome, 4''-6-bis(2'-imidazolinyl-4'-5'H)-2-phenyl-4'-phenoxyindole, visualizes the RNA-containing "partes fibrillares et granulares" of the nucleolus. Both staining procedures can be combined to analyze nucleolar structure and function by light microscopy.
Using a one-step silver nitrate staining technique, routinely processed tumour tissues of 49 carcinomas of the colon were investigated to demonstrate silver-stained nucleoli (Ag-nus) and argyrophilic proteins associated with the so-called nucleolar organizer regions (Ag-NORs). Patients with attempted curative resections and tumour stages Dukes' A, B, C1 and C2, with an uneventful follow-up period of at least 48 months (N = 17), showed a statistically significant (P = 0.0001) lower mean number of scattered Ag-NORs (3.04; SD: 1.08) compared to patients who developed metastases during their follow-up period (N = 15; 5.40; SD: 1.28), as well as to patients who underwent palliative surgical treatment (N = 17; 4.48; SD: 1.67). Mean numbers of scattered Ag-NORs per nucleus and staging of the tumour were strongly related (P = 0.0001) to cancer-specific survival. The results indicate that the evaluation of silver-stained particles according to their different distribution patterns is of great value with regard to the clinical outcome of colonic carcinoma and may even allow a more accurate prognostic assessment of these patients than the WHO grading system, UICC staging system, the so-called Jass-scoring system, and Dukes' classification.
It is widely accepted that the inactivation of P53 tumor suppressor gene is related to the tumorigenesis of many cancers. The study on P53 tumor suppressor gene has become a hotspot in molecular oncology. But until now, the reports on the research of the role of P53 gene in the tumorigenesis and prognosis of oral squamous cell carcinoma are scarce. So, two studies have been carried out. (1) A silver staining method of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis was established by detecting the mobility shifts of the DNA bands of the products of PCR of mutant P53 gene plasmid and the Sup F mutants which had been proved to have point mutation by DNA sequencing in shuttle vector plasmid pS 189 mutagenesised by N-methyl-N-nito-N-nitosoguanidine (MNNG). For the method is non-radiation with high sensitive, it has applicable value. (2) By silver staining PCR-SSCP system, tissues from normal oral mucoas membrane to metastatic oral squamous cell carcinoma (OSCC) were analyzed and the results showed that tissues from 53% oral precancerous lesions and 65% OSCC had abnormal SSCP bands and the abnormal frequency of metastatic cancers was higher than that of nonmetastatic ones. These suggest that P53 gene mutation plays some role on the process of initiation, development and metastasis of OSCC.
A reliable and economical silver staining method is recommended for demonstration of Lewy bodies (LB) and Lewy neurites (LN) in Parkinson's disease (PD) and of argyrophilic oligodendrocytes in multiple system atrophy (MSA). The technique can be applied to routinely formalin-fixed autopsy material and does not require particular skills. It permits processing of frozen sections and sections from polyethylene glycol or paraffin embedded material. It takes advantage of the physical development of nucleation sites and thereby permits tight control of the entire staining procedure.
A new simple modification to the silver staining of nucleolar organiser regions (AgNORs) was devised which, by performing the incubation with the slide inverted, results in minimal undesirable background staining, a persistent problem. Inverted incubation is facilitated by the use of a commercially available plastic coverplate. This technique has several additional advantages over other published staining protocols. In particular, the method is straightforward, fast, and maintains a high degree of contrast between the background and the AgNORs.