Search results
Results from the WOW.Com Content Network
In pap smears, Light Green SF confers a blue staining for the cytoplasm of active cells such as columnar cells, parabasal squamous cells, and intermediate squamous cells. [3] It usually comes as a disodium salt. Its maximum absorption is at 630 (422) nm. The dye is not very durable — it has a tendency to fade.
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.
When the computer calculates a formula in one cell to update the displayed value of that cell, cell reference(s) in that cell, naming some other cell(s), causes the computer to fetch the value of the named cell(s). A cell on the same "sheet" is usually addressed as: =A1 A cell on a different sheet of the same spreadsheet is usually addressed as:
Some staining methods are based on this property. Those stains excluded by the living cells but taken up by the already dead cells are called vital stains (e.g. trypan blue or propidium iodide for eukaryotic cells). Those that enter and stain living cells are called supravital stains (e.g.
A dilution of the cells to be counted is prepared and mixed with Trypan blue, this is normally the stain of choice because it is taken up by dead cells and actively excluded from live cells. Once the cells have been stained, they are counted using a hemocytometer, then a calculation is carried out to the original concentration of live cells. [1]
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.
Safranin (Safranin O or basic red 2) is a biological stain used in histology and cytology. Safranin is used as a counterstain in some staining protocols, colouring cell nuclei red. This is the classic counterstain in both Gram stains and endospore staining. It can also be used for the detection of cartilage, [2] mucin and mast cell granules.
Mauveine is a mixture of four related aromatic compounds differing in number and placement of methyl groups.Its organic synthesis involves dissolving aniline, p-toluidine, and o-toluidine in sulfuric acid and water in a roughly 1:1:2 ratio, then adding potassium dichromate.