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It is important first, to homogenize milk, heating it in a water bath at 40 °C for somatic cells that float to the surface along with the fat. The laboratory apparatus must be clean but not necessarily sterile, since the method is based on cell count and asepsis is not accurate. If later it is going to make detailed microbiological analyzes on ...
A Ziehl–Neelsen stain is an acid-fast stain used to stain species of Mycobacterium tuberculosis that do not stain with the standard laboratory staining procedures such as Gram staining. This stain is performed through the use of both red coloured carbol fuchsin that stains the bacteria and a counter stain such as methylene blue.
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.
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 ...
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.
Carbol fuchsin, carbol-fuchsin, carbolfuchsin, or Castellani's paint (CAS) is a mixture of phenol and basic fuchsin that is used in bacterial staining procedures. It is commonly used in the staining of mycobacteria because it has an affinity for the mycolic acids found in their cell membranes.
Determining the viable cell count is important for calculating dilutions required for the passaging of cells, as well as determining the size and number of flasks needed during growth time. It is also vital when seeding plates for assays, such as the plaque assay , [ 2 ] because the plates need a known number of live replicating cells for the ...
Cresyl violet stained partial brain section of a Macaque. It is used in biology and medicine as a histological stain. Cresyl violet is an effective and reliable stain used for light microscopy sections. Initially, tissue sections are "defatted" by passing through graded dilutions of ethanol. Then, rehydrated by passing back through decreasing ...