SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Stain

166

The quantity of circulating reticulocytes is an important indicator of erythropoietic activity in response to a wide range of haematological pathologies. While most modern laboratories use flow cytometry to quantify reticulocytes, most field laboratories still rely on ‘subvital’ staining. The specialist ‘subvital’ stains, New Methylene Blue (NMB) and Brilliant Crésyl Blue are often difficult to procure, toxic, and show inconsistencies between batches. Here we demonstrate the utility of Giemsa’s stain (commonly used microbiology and parasitology) in a ‘subvital’ manner to provide an accurate method to visualize and count reticulocytes in blood samples from normal and malaria-infected individuals.

Concepts: Flow cytometry, Stain, Reticulocyte, Biology, Hematology, Anemia, New methylene blue, Red blood cell

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Background and Objectives Port-wine stains (PWSs) are capillary vascular malformations that are commonly resistant to treatment. Currently, the pulsed dye laser (PDL) is the treatment of choice. Multiple treatments are required and complete blanching after laser irradiation is rarely achieved. We review current therapeutic modalities for PWSs and recent developments for enhanced clearance.Study Design/Materials and Methods Relevant literature was reviewed including PDL modifications for improved efficacy, alternative laser devices for treatment-resistant PWSs, and the addition of agents to modulate the wound-healing response after laser irradiation.Results Although PDL is the treatment of choice for PWSs, increased understanding of interactions between PWSs and PDL has led to improvements in therapeutic outcome in terms of lesion blanching.Conclusions Preliminary evidence of combination therapy using antiangiogenic agents after laser irradiation appears promising and could lead to the development of a new standard of care for PWSs.

Concepts: Tunable laser, Stain, Laser pumping, Malachite green, Therapy, Laser, Port-wine stain, Dye laser

27

The use of microwave irradiation as a source of energy to clear and stain intra-radical arbuscular mycorrhizal fungi propagules has been tested on a variety of indigenous and cultivated herbaceous plants. The aim of the study was to evaluate the efficiency of microwave irradiation on root softening, fungi tissue staining, and preservation of DNA integrity for subsequent molecular analyses. The proposed methodology has been adapted from the standard procedures used to detect and quantify mycorrhizal root colonization levels. Using a domestic microwave oven, tissue clearing and staining required together between 30 s and 1.5 min of microwave treatment to be completed, depending the diameter size of the roots. The well-performing chemical stains tested were acid fuchsin, trypan blue, and aniline blue. The acid fuchsin clearing and staining processes, as performed, were also demonstrated to preserve DNA integrity for further molecular analyses. Irradiation by microwaves has been used with success in our laboratory within the frame of several studies. It offers considerable time saving over traditional method, reducing processing times from several hours to a few minutes while decreasing considerably the amount of chemicals and energy required to perform analyses.

Concepts: Chemistry, Glomeromycota, Stain, Microwave oven, Fungus, Plant, Arbuscular mycorrhiza, Mycorrhiza

26

Cerebral microbleeds are microscopic hemorrhages with deposits of blood products in the brain, which can be visualized with MRI and are implicated in cerebrovascular diseases. Hematoxylin and eosin (H&E) and Perl’s Prussian blue are popular staining methods used to localize cerebral microbleeds in pathology. This paper compared these two staining techniques in a mouse model of cerebral microbleeds. We used lipopolysaccharide (LPS) to induce cerebral microhemorrhages. C57B6 mice were treated with LPS (5 mg/kg, i.p.) or vehicle at baseline and at 24 hr. The brains were extracted 48 hr after the first injection and adjacent coronal sections were stained with H&E and Prussian blue to compare the effectiveness of the two staining techniques. H&E-positive stains were increased with LPS treatment and were correlated with grossly visible microhemorrhages on the brain surface; Prussian blue-positive stains, by comparison, showed no significant increase with LPS treatment and did not correlate with either H&E-positive stains or surface microhemorrhages. H&E staining is thus a more reliable indicator of acute bleeding events induced by LPS in this model within a short time span.

Concepts: Brain tumor, Traumatic brain injury, Blood, Human brain, Stain, Perls' Prussian blue, Brain, Prussian blue

26

Here we determine an optimal technique for the visualization of extracellular DNA in bacterial biofilms using the fluorescent eDNA stain TOTO-1 and the counterstain SYTO 60. This technique allows for more sensitive eDNA visualization than other fluorescent staining methods currently in use.

Concepts: Counterstain, Stain, Staining

25

We hyposthesized that henna staining could provide an alternative to eosin when used as a counterstain to hematoxylin for understanding basic neurohistological principles. Therefore, this study was aimed at investigating the suitability of henna as counterstain to hematoxylin for the demonstration of the layer stratification and cellular distribution in the brain tissue. Henna stained nervous tissue by reacting with the basic elements in proteins via its amino groups. It stained the neuropil and connective tissue membranes brown and effectively outlined the perikarya of neurons with no visible nuclei demonstrating that it is an acidic dye. Henna as a counterstain to hematoxylin demonstrated reliability as a new neurohistological stain. It facilitated identification of cortical layer stratification and cellular distribution in brain tissue sections from Wistar rats. This was comparable to standard hematoxylin and eosin staining as morphological and morphometrical analyses of stained cells did not show significant differences in size or number. This study presents a method for staining with henna and demonstrates that although henna and eosin belong to different dye groups (anthraquinone and xanthenes, respectively) based on their chromophores, they share similar staining techniques and thus could be used interchangeably in neurohistology.

Concepts: Counterstain, Stain, Brain, Demonstration, Nervous system, Human brain, Cerebral cortex, Neuron

25

Bronchopulmonary lophomoniasis (BPL) is an emerging disease of potential importance. BPL is presented by non-specific clinical picture and is usually accompanied by immunosuppression. Culture of Lophomonas blattarum is difficult and its molecular diagnosis has not yet been developed. Therefore, microscopic examination of respiratory samples, e.g., bronchoalveolar lavage (BAL) or sputum, is the mainstay of BPL diagnosis. Creola bodies and ciliocytophthoria are two forms of bronchial cells which occur in chest diseases with non-specific clinical picture like that of BPL. Both forms could be misrecognized as multi-flagellates because of their motile cilia in the wet mounts and due to shape variability of L. blattarum in stained smears. The aim of the study is to compare different staining techniques for visualizing L. blattarum to improve the recognition and diagnosis of BPL, to distinguish respiratory epithelial cells from L. blattarum and to decide which stain is recommended in suspected cases of BPL. BAL samples from patients which contain L. blattarum, creola bodies, and ciliocytophthoria were collected then wet mounts were examined. The BAL samples were also stained by Papanicolaou (PAP), Giemsa, hematoxylin and eosin (H & E), trichrome, Gram, and Diff-Quik (DQ) stains. The different staining techniques were compared regarding the stain quality. In wet mounts, the ciliary movement was coordinate and synchronous while the flagellar movement was wavy and leaded to active swimming of L. blattarum. In stained slides, bronchial cells were characterized by the presence of basal nucleus and the terminal bar from which the cilia arise. Trichrome was the best stain in demonstration of cellular details of L. blattarum. H & E, PAP, and Giemsa stains showed good quality of stains. Gram and DQ stains showed only pale hues of L. blattarum. We recommended adding Wheatley’s trichrome staining to the differential diagnosis workup of cases of non-specific chest infections, especially when BPL is suspected, to avoid overdiagnosis or underdiagnosis of it.

Concepts: Differential diagnosis, Gram staining, Wright's stain, Medical diagnosis, Giemsa stain, Microscope, Stain, Staining

25

Peripheral blood and bone marrow smear examination is an important basic tool for the diagnosis of different haematological conditions including haematological malignancies. We created a newer modification of the conventional Leishman and Giemsa stains as Leishman and Giemsa (L&G) stain and compared the efficacy and reliability of this stain with conventional stains. The study was performed to evaluate the staining efficacy, feasibility, time and cost of L&G stain over the conventional Leishman and Giemsa stains.

Concepts: Gram staining, Stain, Leukemia, Blood, Wright's stain, Staining, Giemsa stain, Bone marrow

25

Uranyl acetate (UAc) has been generally used not only as a superb staining reagent for ultrathin sections of plastic-embedded biological materials, but also as high-contrast negative stains for biological macromolecules such as particles of protein or virus. However, the use and purchase of radioactive UAc have been restricted. In this study, we determine the performance of ytterbium triacetate, lutetium triacetate, samarium triacetate and gadolinium triacetate as new staining reagents for biological electron microscopy. We observed chemically fixed spinach (Spinacia oleracea) leaves stained with these reagents. Ultrathin sections were stained with these reagents. Some of them were counterstained with lead citrate. The transmission electron microscopy contrast of spinach organelles was evaluated in sections exposed to the conventional stain and new stains. We show acetate salts of samarium, gadolinium, ytterbium and lutetium could be excellent substitutes for UAc for thin section staining and for negative staining. In addition, each reagent showed appreciable negative-staining effects.

Concepts: Lanthanide, Microscope, Negative stain, Stain, Biology, Rare earth element, Staining, Transmission electron microscopy

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Acanthamoeba is one of the most common free-living amoebae. It is widespread in the environment and can infect humans causing keratitis. Delayed diagnosis or misdiagnosis leads to extensive corneal inflammation and profound visual loss. Therefore, accurate and rapid diagnosis of Acanthamoeba keratitis is essential for successful treatment and good prognosis. This study was designed to use different staining techniques to facilitate the identification of Acanthamoeba cysts. Acanthamoeba cysts were isolated by cultivation of either corneal scraping specimens or tap water samples onto non-nutrient agar plates seeded with Escherichia coli. Subcultures were done from positive cultures until unique cysts were isolated. Acanthamoeba cysts were stained temporarily using iodine, eosin, methylene blue, and calcofluor white (CFW) stains and as permanent slides after processing for mounting using modified trichrome, Gimenez and Giemsa staining. These stains were compared on the basis of staining quality including clarity of morphological details, differentiation between cytoplasm and nuclei, color and contrast, and also other characteristics of the staining techniques, including ease of handling, time taken for the procedure, and cost effectiveness. The cysts of Acanthamoeba were recognized in the form of double-walled cysts: the outer wall (ectocyst) that was being differentiated from the variably stained surrounding background and the inner wall (endocyst) that was sometimes stellated, polygonal, round, or oval and visualized as separate from the spherical, sometimes irregular, outline of the ectocyst. Regarding the temporary stains, it was found that they were efficient for visualizing the morphological details of Acanthamoeba cysts. In CFW staining, Acanthamoeba cysts appeared as bluish-white or turquoise oval halos although the internal detail was not evident. On the other hand, the results of permanent-stained slides showed the most consistent stain for identification of Acanthamoeba cysts was modified trichrome followed by Gimenez stain and lastly Giemsa stain that gave poor visibility of Acanthamoeba cysts due to the intense staining background and monochrome staining of parasite. In the present study, multi-attribute ranking of the used staining techniques showed the highest rank for iodine stain (92 %) followed by eosin stain (84 %), Gimenez stain (76 %), methylene blue (72 %), CFW (64 %), modified trichrome (56 %), and the least was Giemsa stain (44 %). In conclusion, the staining techniques enhance the overall visibility of Acanthamoeba cysts.

Concepts: Counterstain, Stain, Giemsa stain, Staining