A sensitive silver stain for proteins in agarose gels

A silver stain for proteins in agarose gels which is at least 10 times as sensitive as Coomassie blue is described. The method is simple to use and is particularly useful for the study of protein bands in the gamma region on electrophoresis of fluids such as cerebrospinal fluid in which the protein concentration is low. It readily detects bands of IgG containing 20 to 40 ng/band (approx 3 to 6 ng of IgG/mm2 of gel).     

A sensitive silver stain for detecting lipopolysaccharides in polyacrylamide gels

A sensitive silver stain for detecting bacterial lipopolysaccharides in polyacrylamide gels is developed by modifying the silver-staining method used for proteins (cf. R. C. Switzer III, C. R. Merril, and S. Shifrin, Anal. Biochem.98, 231–237 (1979). Lipopolysaccharides are analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate followed by visualization with either the modified silver stain or periodic acid-Schiff stain. The lipopolysaccharides are stained dark brown by the silver stain. The silver stain is 500 times more sensitive than the periodic acid-Schiff stain and can detect less than 5 ng of rough type lipopolysaccharides. Analyses of 5μg of smooth-type lipopolysaccharides from Salmonella typhimurium and Escherichia coli O111: B4 show each to have 30–40 components of different molecular weights. The use of a lipopolysaccharide having a known structure and variable numbers of repeating units in the O side chain, such as one of the two lipopolysaccharides mentioned above, as molecular weight markers is proposed for the estimation of the molecular weights of other lipopolysaccharides or their components. The lipopolysaccharides can also be stained grayish green, but become grayish blue with a heavy sample load, using a silver-based color-staining method (D. W. Sammons, L. D. Adams, and E. E. Nishizawa, Electrophoresis2, 135–141 (1981)).     

A silver impregnation technique to demonstrate muscle-bone-cartilage relationships in fishes

A modification of the Winkelmann and Schmitt (1957) technique originally designed to investigate patterns of peripheral nervous innervation is given for demonstration of developing bone growth centers and associated muscle origins and insertions in larval and small fishes. This technique offers a simpler and faster way of obtaining such ontogenetic information than the standard method of double staining with alizarin red S and Alcian blue followed by clearing with potassium hydroxide. Muscles also stain, facilitating the location of their origins and insertions.     

A rapid sensitive silver stain for polypeptides in polyacrylamide gels

The use of silver to detect polypeptides was originally achieved by modifying tissue stains. By adapting methods of photochemistry we have developed a new silver stain for polypeptides which is nearly as sensitive but much more efficient than these earlier procedures. The new silver stain utilizes only three solutions and allows protein patterns to be visualized within 50 min. Its sensitivity is 100 times that of the Coomassie blue stain.     

A silver staining reaction for chromosomes and nuclei

Summary A staining reaction for the nucleus and chromosomes, using silver-hexamethylentetramine, buffered with borax, after hydrolisis with warm IN HC1, has been proposed. Its specificity has been assayed by means of enzymatic digestions (DNase, pepsin, trypsin), and through the comparison of the results with those obtained by the Feulgen reaction.This staining method bears the advantage, compared to the usual methods, of a noteworthy photographic contrast.Moreover this method is probably specific for the DNA containing structures, because of the lack of stainability of nuclear structures, after DNase digestion.

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Riassunto E'stata proposta, per il nucleo ed i cromosomi, una reazione con argentoesa-metilentetrammina, tamponata con borace, previa idrolisi acida con HC1 1N, a caldo, e ne è stata saggiata la specificità mediante digestioni enzimatiche (DNAasi, pepsina, tripsina) e confronto dei risultati ottenuti con la reazione di Peulgen.Questa colorazione presenta il vantaggio, rispetto alle usuali colorazioni, di un notevole contrasto fotografico.Inoltre la non colorabilità delle strutture nucleari, dopo digestione con DNAasi, lascia supporre una specificità del metodo per le strutture contenenti DNA.

     

A silver method for counterstaining plastic embedded tissue

This report presents a method which can be used for counterstaining semithin sections of plastic embedded tissue. The sections are treated with a solution of silver lactate, followed by physical development. During the silver lactate treatment, silver ions are bound by various tissue components as metallic silver or silver sulfide. During physical development catalytic reduction of silver ions to metallic silver takes place where silver has been bound in the tissue, enlarging the silver deposits to microscopically visible dimensions. The amplified silver deposits give high contrast staining in yellow, brown and black suitable for both color and monochrome photography. The localization of the silver deposits is highly specific and may reflect several independent chemical processes. Examples in several tissues are shown.     

A method for silver impregnation of mammary myoepithelia

Histochemical methods for microscopic visualization of mammary myoepithelial cells all yielded considerable variation in completeness of myoepithelial cell staining. Although extremely variable, silver impregnation occasionally gave tissue sections containing myoepithelia having excellent microanatomical detail and contrast with other tissue elements. Consequently, sources of variation in the silver technique were considered. Composition of the tissue fixative and pH of the silver impregnating solution were most critical. A final method is presented which gives consistent, complete silver impregnation of myoepithelia, where both the cell body and cell processes are clearly evident. The staining procedure is not light sensitive, nor is acid cleaning of glassware necessary. Tissue sections from lactating mouse, rat, hamster and goat are presented; tissue from other species should stain as well. The procedure should greatly facilitate the study of the function of myoepithelial cells and the visualization of these cells in mammary pathology.     

A method for combined C-banding and silver staining

A reliable technique for combined C-banding and silver staining of metaphase chromosomes which uses trypsinization is described. Slides are first immersed in dilute HCl to remove residual cytoplasm from around the chromosomes. They are then treated with saturated barium hydroxide and incubated overnight in saline sodium citrate (0.30 M NaCl, 0.03 M sodium citrate, adjusted to pH 7.0 with HCl). Following the C-banding pretreatment, a two-step method of silver staining which employs a protective colloidal developer is used to stain the nucleolar organizer regions (NORs) of the chromosomes. Silver staining is followed by trypsinization to remove extraneous silver precipitate from the chromosome arms which permits the C-bands to be stained with Giemsa. The method works equally well with fresh and aged mitotic chromosome preparations and gives consistent staining of both heterochromatin and active NORs in metaphases across the slide.     

A mass spectrometry compatible silver staining method for protein incorporating a new silver sensitizer in sodium dodecyl sulfate-polyacrylamide electrophoresis gels

A quick, sensitive, and MALDI-TOF MS compatible silver staining method, namely Eriochrome black T (EBT)-silver method, is described. The method can detect 0.05-0.2 ng protein within 60 min in SDS-PAGE gels. EBT dye was used as a silver ion sensitizer having reducing power for silver ions.     

A simplified ultrasensitive silver stain for detecting proteins in polyacrylamide gels

We have simplified the highly sensitive silver stain of R. C. Switzer III, C. R. Merril, and S. Shifrin (1979, Anal. Biochem.98, 231–237) for visualizing proteins in polyacrylamide gels. We have reduced the number of steps in the procedure from 10 to 6, simplified the reagents in each step, and reduced the amount of silver required by a factor of 10, thus greatly reducing the expense of the procedure. In common with the original silver stain, our procedure is 100 times more sensitive than Coomassie brilliant blue and is comparable in sensitivity to radioautography of radioactively labeled proteins.     

A modified silver method for demonstrating developing nervous tissue in culture

Dissociated explants of 8-day-old embryonic chick cerebrum were cultured for up to 18 days. By the beginning of the 2nd week and thereafter, primary cultures of neurons exhibited characteristic differentiated morphology with an interconnecting neurofibrillary network that became increasingly ramified. Neurons in bipolar, tripolar or multipolar form could be demonstrated positively using a short modified silver impregnation method with potassium ferrocyanide.     

纳米银体外抗腺病毒作用初步研究

目的探讨纳米银(silver nanoparticles,silver-nps)在体外对腺病毒3型(Adenovirus type 3,ADV3)的抑制作用。方法运用细胞培养技术、MTT测值法、CPE和免疫荧光观察法,分析纳米银对ADV3感染HeLa细胞的预防作用、直接灭活作用以及对ADV3子代病毒体生成的抑制作用。结果纳米银能明显杀伤ADV3,且呈剂量依赖性;纳米银在HeLa细胞上最大无毒浓度(TC0)为52.48μg/ml;ADV3在HeLa细胞上的组织半数感染量(TCID50)为10-2.74/100μl;最大无毒剂量范围内,50、25、12.5、6.25和3.125μg/ml的纳米银分别与100 TCID50ADV3等体积混合,细胞存活率分别为(95.38±2.60)%、(60.51±9.42)%、(57.99±8.72)%、(41.35±3.91)%和(37.88±3.75)%,而100 TCID50ADV3感染HeLa细胞后,测得细胞存活率为(31.92±8.98)%,二者相比差异有统计学意义(P0.05);免疫荧光结果显示,与纯病毒组形成的强特异性荧光相比,纳米银在ADV3吸附细胞后加入、吸附前预处理HeLa细胞和纳米银同ADV3同时作用三种途径特异性荧光都很少见,说明纳米银在不同途径下对ADV3均有抑制作用。结论纳米银对腺病毒3型具有明显的抑制作用。