A simple technique for the preservation of vital dyes in fixed and sectioned embryos

Development ◽  
1966 ◽  
Vol 15 (2) ◽  
pp. 131-132
Author(s):  
J. Pertusa
Keyword(s):  
Methylene Blue ◽  
Ethyl Alcohol ◽  
Toluidine Blue ◽  
Trypan Blue ◽  
Simple Technique ◽  
Nile Blue ◽  
Neutral Red ◽  
The Other ◽  
Serial Sectioning ◽  
Vital Dyes

In embryological work using vital dyes it is highly desirable to be able to study the distribution of the dyes in fixed material, whether examined in toto or after embedding in paraffin and serial sectioning. However, both fixation and dehydration present problems for the preservation of colour in vitally stained cells. Some fixatives preserve some dyes but, so far as I am aware, none will preserve all the vital dyes in common use. On the other hand, ethyl alcohol destroys or dissolves all vital dyes and its use in dehydration is thus undesirable. Among the fixatives that have been proposed are those of Golowin (1902), Mitamura (1923), Parat & Painlevé (1925), and Tchéou Tai Chuin (1930) for neutral red; that of Izquierdo (1955) for toluidine blue; that of Gérard (1925) for Trypan blue; that of Turchini (1919) for methylene blue; that of Lehmann (1929) for Nile blue.

Properties of oral asaccharolytic black-pigmented Bacteroides

1984 ◽  
Vol 30 (9) ◽  
pp. 1133-1136 ◽  
Author(s):  
D. Mayrand ◽  
G. Bourgeau ◽  
D. Grenier ◽  
J.-M. Lacroix
Keyword(s):  
Methylene Blue ◽  
Congo Red ◽  
Neutral Red ◽  
Enzymatic Activities ◽  
The Other ◽  
Other Hand ◽  
Inhibitory Agents ◽  
Group B

Bacteroides endodontalis, a newly described asaccharolytic black-pigmented Bacteroides, along with the other two recognized species of this group (B. gingivalis and B. asaccharolyticus) were studied for their susceptibility to various dyes and inhibitory agents and for some of their enzymatic activities to facilitate differentiating between them. Bacteroides endodontalis resembles B. asaccharolyticus physiologically except for the fact that the former cannot grow on media containing methylene blue, neutral red, or 3% sodium choride, whereas B. asaccharolyticus can. On the other hand, B. endodontalis and B. gingivalis can grow on a medium containing Congo red while B. asaccharolyticus cannot.

The Vital Staining of Amoeba Proteus

1963 ◽  
Vol s3-104 (68) ◽  
pp. 445-458
Author(s):  
JENNIFER M. BYRNE
Keyword(s):  
Nile Blue ◽  
Vital Staining ◽  
Neutral Red ◽  
Amoeba Proteus ◽  
Methyl Green ◽  
Pronounced Increase ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Vital Dyes ◽  
Food Vacuoles

The effect of keeping Amoeba proteus in dilute basic dye solutions was studied. It was found that Nile blue, neutral red, and neutral violet in particular, and also brilliant cresyl blue, methylene blue, Bismarck brown, thionin, toluidine blue, and azures A and B act as vital dyes, while at comparable molarities crystal violet, dahlia, safranin, methyl green, Janus green, and Victoria blue are lethal, and do not produce any staining until after death. Azure C, basic fuchsin, and particularly pyronine G are relatively harmless, but produce no vital staining. All the vital dyes stain the food vacuoles, and all produce small, darkly stained granules in colourless vacuoles in the cytoplasm. The latter do not exist in the unstained amoeba. Some of the dyes colour vacuoles around the crystals. These crystal vacuoles also seem to be induced. A few of the dyes colour the spherical refractive bodies, which are at least in part phospholipid. All the basic dyes used with the possible exception of azure C, methyl green, and pyronine G attach to the external membrane of A. proteus in an orientated manner, as shown by the increase in birefringence of the external membrane induced by these dyes. It is particularly those dyes that act as vital dyes that produce a very pronounced increase in the birefringence of the external membrane.

The indicator system of the Sabin-Feldman phenomenon in Toxoplasma

Parasitology ◽  
1960 ◽  
Vol 50 (1-2) ◽  
pp. 13-20
Author(s):  
C. Kulasiri
Keyword(s):  
Toluidine Blue ◽  
Nile Blue ◽  
Neutral Red ◽  
Indicator System ◽  
Alkaline Solutions ◽  
Methyl Green ◽  
Celestine Blue ◽  
Cresyl Blue ◽  
Azure B ◽  
Saline Solutions

Azure A, azure B and Nile blue in both neutral and alkaline solutions were found to be suitable for use as indicator dyes in the Sabin-Feldman test. Toluidine blue, brilliant cresyl blue and thionine were also suitable as neutral solutions. Azure C, phloxine, phloxine B, neutral red, methyl green, pyronine Y, eosin and celestine blue were found to be unsuitable. Azure B and toluidine blue in saline solutions were serviceable up to 5 months after preparation. The significance of these findings is discussed.

A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

1971 ◽  
Vol 29 ◽  
pp. 358-359
Author(s):  
B. J. Panessa ◽  
J. F. Gennaro
Keyword(s):  
Methylene Blue ◽  
Toluidine Blue ◽  
Outer Surface ◽  
Microscope Study ◽  
Light Microscope ◽  
Carnivorous Plant ◽  
Sarracenia Purpurea ◽  
Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

Method for the Quantification of Alginate in Microcapsules

1993 ◽  
Vol 2 (5) ◽  
pp. 429-436 ◽  
Author(s):  
Jean-Pierre Hallé ◽  
Danielle Landry ◽  
Alain Fournier ◽  
Michèle Beaudry ◽  
Francois A. Leblond
Keyword(s):  
Methylene Blue ◽  
Alkaline Medium ◽  
High Sensitivity ◽  
Sodium Concentration ◽  
The Other ◽  
Sensitive Assay ◽  
Reliable Measurement ◽  
Alginate Concentration ◽  
Other Substances ◽  
Alginate Content

Alginate is a key reagent in the preparation of microcapsules for cell transplantation. To address the question of the intracapsular alginate concentration, a sensitive assay has been developed to quantify the alginate content of microcapsules. The method is based on the metachromatic change induced by alginate binding to the dye, 1,9-dimethyl methylene blue (DMMB). The assay has a high sensitivity and precision. It covers a wide concentration range enabling the measurement of alginate in dilute supernatants as well as in microcapsules. For the latter, the membrane is initially dissolved by incubating the microcapsules in an alkaline medium. The effect of potentially interfering substances (poly-l-lysine (PLL), citrate, chloride, sodium) and of pH has been studied. Poly-l-lysine interfered with the assay at pH 6.5 but not at pH 13. Interference by sodium augmented with increasing sodium concentration and reached a plateau at 200 mM. This problem was overcome by routinely adjusting all samples to 500 mM sodium. The other substances tested had a negligible effect on the assay. The reliable measurement of alginate with this new assay will allow the optimization of the intracapsular alginate concentration.

scholarly journals Label-free cell based impedance measurements of ZnO nanoparticles—human lung cell interaction: a comparison with MTT, NR, Trypan blue and cloning efficiency assays

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Giuseppina Bozzuto ◽  
Giuseppe D’Avenio ◽  
Maria Condello ◽  
Simona Sennato ◽  
Ezio Battaglione ◽  
...  
Keyword(s):  
Trypan Blue ◽  
A549 Cells ◽  
Cell Interaction ◽  
Neutral Red ◽  
Free Cell ◽  
Mitogenic Activity ◽  
Label Free ◽  
Cloning Efficiency ◽  
Zno Nps ◽  
Experimental Conditions

Abstract Background There is a huge body of literature data on ZnOnanoparticles (ZnO NPs) toxicity. However, the reported results are seen to be increasingly discrepant, and deep comprehension of the ZnO NPs behaviour in relation to the different experimental conditions is still lacking. A recent literature overview emphasizes the screening of the ZnO NPs toxicity with more than one assay, checking the experimental reproducibility also versus time, which is a key factor for the robustness of the results. In this paper we compared high-throughput real-time measurements through Electric Cell-substrate Impedance-Sensing (ECIS®) with endpoint measurements of multiple independent assays. Results ECIS-measurements were compared with traditional cytotoxicity tests such as MTT, Neutral red, Trypan blue, and cloning efficiency assays. ECIS could follow the cell behavior continuously and noninvasively for days, so that certain long-term characteristics of cell proliferation under treatment with ZnO NPs were accessible. This was particularly important in the case of pro-mitogenic activity exerted by low-dose ZnO NPs, an effect not revealed by endpoint independent assays. This result opens new worrisome questions about the potential mitogenic activity exerted by ZnO NPs, or more generally by NPs, on transformed cells. Of importance, impedance curve trends (morphology) allowed to discriminate between different cell death mechanisms (apoptosis vs autophagy) in the absence of specific reagents, as confirmed by cell structural and functional studies by high-resolution microscopy. This could be advantageous in terms of costs and time spent. ZnO NPs-exposed A549 cells showed an unusual pattern of actin and tubulin distribution which might trigger mitotic aberrations leading to genomic instability. Conclusions ZnO NPs toxicity can be determined not only by the intrinsic NPs characteristics, but also by the external conditions like the experimental setting, and this could account for discrepant data from different assays. ECIS has the potential to recapitulate the needs required in the evaluation of nanomaterials by contributing to the reliability of cytotoxicity tests. Moreover, it can overcome some false results and discrepancies in the results obtained by endpoint measurements. Finally, we strongly recommend the comparison of cytotoxicity tests (ECIS, MTT, Trypan Blue, Cloning efficiency) with the ultrastructural cell pathology studies. Graphic Abstract

An Approximate Analysis of Circular Plates With Variable Thickness

1982 ◽  
Vol 104 (3) ◽  
pp. 533-535
Author(s):  
A. K. Naghdi
Keyword(s):  
Variable Thickness ◽  
Simple Technique ◽  
Bending Moment ◽  
The Other ◽  
Uniform Pressure ◽  
Approximate Analysis ◽  
Circular Plates ◽  
Numerical Examples ◽  
Classic Theory ◽  
Rotationally Symmetric

Based on classic theory of beams and certain modifications, a simple technique is derived in order to obtain an approximate value of the maximum bending moment in a rotationally symmetric circular plate with a variable thickness. It is assumed that one of the two concentric boundaries of the plate is clamped, and the other is free. Numerical examples for both cases of constant and variable thickness plates subject to uniform pressure or rim line loading are presented.

scholarly journals Methemoglobin Reduction

Blood ◽  
1963 ◽  
Vol 22 (3) ◽  
pp. 323-333 ◽  
Author(s):  
ERNEST BEUTLER ◽  
MARYELLEN C. BALUDA
Keyword(s):  
Methylene Blue ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Nile Blue ◽  
Transport Chain ◽  
Rate Of Accumulation

Abstract 1. It has been shown that mixtures of normal and G-6-PD deficient nitrite-treated erythrocytes reduced methemoglobin at a rate considerably more rapid than that computed from their individual rates of methemoglobin reduction. 2. Differential agglutination studies demonstrated that when normal, methemoglobin-containing cells in such a mixture have reduced all of their methemoglobin, they facilitate methemoglobin reduction in G-6-PD deficient erythrocytes. 3. The same effect could be observed in other mixtures of cells, (e.g., normal with normal, G-6-PD deficient with G-6-PD deficient, etc.) and even with highly purified methemoglobin solutions. 4. This effect could be observed in the presence of methylene blue but not in the presence of another redox dye, Nile blue sulfate. 5. Lactate served as an effective substrate for methemoglobin reduction. Methemoglobin reduction by lactate was enhanced by methylene blue but not by Nile blue sulfate. 6. In mixtures of normal and G-6-PD deficient erythrocytes, no deficit in the rate of accumulation of lactate was found. This indicates that the mechanism of enhancement of methemoglobin reduction is not the diffusion of lactate from non-methemoglobin-containing cells to methemoglobin-containing cells. 7. It was demonstrated that leukomethylene blue could reduce highly purified solutions of methemoglobin in the absence of the enzyme "methemoglobin reductase." 8. The possible mechanism by which non-methemoglobin-containing cells may reduce methemoglobin in methemoglobin-containing cells is discussed. It seems most probable that leukomethylene blue is the mediator of the effect. This implies, contrary to earlier suggestions, that "methemoglobin reductase" acts prior to the reduction of methylene blue in the electron transport chain.

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