Crystal violet in the context of "Carl Benda"

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⭐ Core Definition: Crystal violet

Crystal violet or gentian violet, also known as methyl violet 10B or hexamethyl pararosaniline chloride, is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Crystal violet has antibacterial, antifungal, and anthelmintic (vermicide) properties and was formerly important as a topical antiseptic. The medical use of the dye has been largely superseded by more modern drugs, although it is still listed by the World Health Organization.

The name gentian violet was once used for a mixture of methyl pararosaniline dyes (methyl violet), but it is considered a synonym for crystal violet. The name refers to its colour, being like that of the petals of certain gentian flowers; it is not made from gentians or violets.

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👉 Crystal violet in the context of Carl Benda

Carl Benda (30 December 1857 Berlin – 24 May 1932 Turin) was one of the first microbiologists to use a microscope in studying the internal structure of cells. In an 1898 experiment using crystal violet as a specific stain, Benda first became aware of the existence of hundreds of these tiny bodies in the cytoplasm of eukaryotic cells and assumed that they reinforced the cell structure. Because of their tendency to form long chains, he coined the name mitochondria ("thread granules"). These bodies had first been noted in 1857 by the physiologist and pioneer of the light microscope, Albert von Kölliker, and were later termed "bioblasts" by Richard Altmann in 1886.

Benda studied medicine in Berlin, Heidelberg, Vienna and Paris, and received his doctorate in medicine in 1881. From there he became an assistant in the pathology institute in Halle (Saale) and Göttingen and the physiology institute in Berlin. In 1888 he earned his habilitation in anatomy in Berlin. From 1894 to 1907 he was prosector at the Stadt-Krankenhaus am Urban, and was titular professor from 1899. From 1908 to 1925 at the Institute of Pathology Krankenhaus Moabit. In 1921 he became emeritus professor until 1925 when he retired. His son was the doctor Clemens Ernst Benda (1898-1975).

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Crystal violet in the context of Gram-negative bacteria

Gram-negative bacteria are bacteria that, unlike Gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan cell wall sandwiched between an inner (cytoplasmic) membrane and an outer membrane. These bacteria are found in all environments that support life on Earth.

Within this category, notable species include the model organism Escherichia coli, along with various pathogenic bacteria, such as Pseudomonas aeruginosa, Chlamydia trachomatis, and Yersinia pestis. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and the antimicrobial enzyme lysozyme produced by animals as part of their innate immune system. Furthermore, the outer leaflet of this membrane contains a complex lipopolysaccharide (LPS) whose lipid A component can trigger a toxic reaction when the bacteria are lysed by immune cells. This reaction may lead to septic shock, resulting in low blood pressure, respiratory failure, reduced oxygen delivery, and lactic acidosis.

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Crystal violet in the context of Gram-positive bacteria

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 type of cell wall.

The Gram stain is used by microbiologists to place bacteria into two main categories, Gram-positive (+) and Gram-negative (−). Gram-positive bacteria have a thick layer of peptidoglycan within the cell wall, and Gram-negative bacteria have a thin layer of peptidoglycan.

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Crystal violet in the context of Gram stain

Gram stain (Gram staining or Gram's method) is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. It may also be used to diagnose a fungal infection. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique in 1884.

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. They are stained pink or red by the counterstain, commonly safranin or fuchsine. Lugol's iodine solution is always added after addition of crystal violet to form a stable complex with crystal violet that strengthens the bonds of the stain with the cell wall.

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LINKED FROM (PARENTS)
← Gram-negative bacteria ← Gram-negative bacterium ← Carl Benda ← Gram-positive bacteria ← Gram stain ← Gram staining ← Gram-negative ← Gram-positive
LINKS TO (CHILDREN)
Triphenylmethane → Histological → Gram staining → Antibacterial → Antifungal medication → Anthelmintic → Topical → Antiseptic → World Health Organization → Pararosaniline → Methyl violet → Petal → Gentiana → List of plants known as violet →