Gram stain or Gram staining, also called Gram's method, is a method of staining used to distinguish and classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique.
Gram staining (or Gram's method) is a way of classifying bacteria into two large groups: gram-positive and gram-negative. The name comes from its inventor, Hans Christian Gram. Gram's method stains bacteria according to the chemical and physical properties of their cell walls. First, a violet dye is put on the bacteria.
Gram stain or Gram staining, also called Gram's method, is a method of staining used to distinguish and classify bacterial species into two large groups (gram-positive and gram-negative). The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique.
Gram staining is used to determine gram status to classifying bacteria broadly based on the composition of their cell wall. Gram staining uses crystal violet to stain cell walls, iodine (as a mordant), and a fuchsin or safranin counterstain to (mark all bacteria).
Safranin (also 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.
- 350.85 g·mol−1
Along with cell shape, Gram staining is a rapid diagnostic tool and once was used to group species at the subdivision of Bacteria. Historically, the kingdom Monera was divided into four divisions based on Gram staining: Firmacutes (+), Gracillicutes (−), Mollicutes (0) and Mendocutes (var.).
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- Importance of the outer cell membrane in bacterial classification
- Bacterial transformation
In bacteriology, Gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their cell wall. 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 peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest
In general, the following characteristics are present in gram-positive bacteria: Cytoplasmic lipid membrane Thick peptidoglycan layer Teichoic acids and lipoids are present, forming lipoteichoic acids, which serve as chelating agents, and also for certain types of adherence. Peptidoglycan chains are cross-linked to form rigid cell walls by a bacterial enzyme DD-transpeptidase. A much smaller volume of periplasm than that in gram-negative bacteria. Only some species have a capsule, usually consis
Along with cell shape, Gram staining is a rapid method used to differentiate bacterial species. Such staining, together with growth requirement and antibiotic susceptibility testing, and other macroscopic and physiologic tests, forms the full basis for classification and subdivision of the bacteria. Species identification hierarchy in clinical settings Historically, the kingdom Monera was divided into four divisions based primarily on Gram staining: Firmicutes, Gracilicutes, Mollicutes and Mendo
Although bacteria are traditionally divided into two main groups, gram-positive and gram-negative, based on their Gram stain retention property, this classification system is ambiguous as it refers to three distinct aspects, which do not necessarily coalesce for some bacterial species. The gram-positive and gram-negative staining response is also not a reliable characteristic as these two kinds of bacteria do not form phylogenetic coherent groups. However, although Gram staining response is an e
In the classical sense, six gram-positive genera are typically pathogenic in humans. Two of these, Streptococcus and Staphylococcus, are cocci. The remaining organisms are bacilli and can be subdivided based on their ability to form spores. The non-spore formers are Corynebacterium and Listeria, whereas Bacillus and Clostridium produce spores. The spore-forming bacteria can again be divided based on their respiration: Bacillus is a facultative anaerobe, while Clostridium is an obligate anaerobe.
Transformation is one of three processes for horizontal gene transfer, in which exogenous genetic material passes from a donor bacterium to a recipient bacterium, the other two processes being conjugation and transduction. In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium. As of 2014 about 80 species of bacteria were known to be capable of transformation, about evenly divided between gram-positive and gram
Jun 25, 2020 · Gram staining is a quick procedure used to look for the presence of bacteria in tissue samples and to characterise bacteria as Gram-positive or Gram-negative, based on the chemical and physical properties of their cell walls. The Gram stain should almost always be done as the first step in diagnosis of a bacteria infection.
I think the procedure how gram staining is done is important enought to be mentioned in Wikipedia. Not in a Howto style; listing the basic steps should be enought. Besides the Picture is good, but a photo showing gram positive an d negative bacteria side by side would be much better. -- Thewob 20:51, 4 November 2005 (UTC)
Jan 30, 2019 · Gram staining is basically a staining technique which is broadly used in microbial and molecular biology. This technique was developed by a Danish bacteriologist Hans Christian Gram in 1884. Gram staining is used for the identification and differentiation of different types of bacteria.
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