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Crystal violet is also used as a tissue stain in the preparation of light microscopy sections. [15] In laboratory, solutions containing crystal violet and formalin are often used to simultaneously fix and stain cells grown in tissue culture to preserve them and make them easily
The Gram-positive cell wall is characterized by the presence of a very thick peptidoglycan layer, which is responsible for the retention of the crystal violet dyes during the Gram staining procedure. It is found exclusively in organisms belonging to the Actinomycetota (or high %G+C Gram-positive organisms) and the Bacillota (or low %G+C Gram ...
This image shows a cross-section of the vascular tissue in a plant stem. Bright-field microscopy ( BF ) is the simplest of all the optical microscopy illumination techniques. Sample illumination is transmitted (i.e., illuminated from below and observed from above) white light , and contrast in the sample is caused by attenuation of the ...
Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick layer of peptidoglycan in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test.
Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out on addition of ethanol.
Cell counting is any of various methods for the counting or similar quantification of cells in the life sciences, including medical diagnosis and treatment. It is an important subset of cytometry , with applications in research and clinical practice.
Toluidine blue is often used to identify mast cells, by virtue of the heparin in their cytoplasmic granules. [3] It is also used to stain proteoglycans and glycosaminoglycans in tissues such as cartilage. The strongly acidic macromolecular carbohydrates of mast cells and cartilage are coloured red by the blue dye, a phenomenon called metachromasia.
In hemocytometry, Türk's solution (or Türk's fluid) is a hematological stain (either crystal violet or aqueous methylene blue) prepared in 99% acetic acid (glacial) [1] and distilled water. The solution destroys the red blood cells and platelets within a blood sample (acetic acid being the main lyzing agent ), and stains the nuclei of the ...