Fuchsine (sometimes spelled fuchsin) or rosaniline hydrochloride is a
magenta
Magenta () is a color that is variously defined as pinkish- purplish-red, reddish-purplish-pink or mauvish-crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blue. I ...
dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...
with
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
C
20H
19N
3·HCl.
["Basic chemical data"](_blank)
''Discovery Series'' online database, Developmental Therapeutics Program, U.S. National Institutes of Health. Retrieved on 2007-10-08. There are other similar chemical formulations of products sold as fuchsine, and several dozen other synonyms of this molecule.
It becomes magenta when dissolved in
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
; as a
solid
Solid is one of the State of matter#Four fundamental states, four fundamental states of matter (the others being liquid, gas, and Plasma (physics), plasma). The molecules in a solid are closely packed together and contain the least amount o ...
, it forms dark
green
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
s. As well as dying
textile
Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...
s, fuchsine is used to
stain
A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials app ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
and sometimes as a
disinfectant
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...
. In the literature of biological stains the name of this dye is frequently misspelled, with omission of the
terminal -e, which indicates an
amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...
. American and English dictionaries (Webster's, Oxford, Chambers, etc.) give the correct spelling, which is also used in the literature of industrial dyeing. It is well established that production of fuchsine results in development of bladder cancers by production workers. Production of magenta is listed as a
circumstance known to result in cancer.
History
Fuchsine was first created by
Jakub Natanson
Jakub Natanson (20 August 1832 – 14 September 1884) was a Polish chemist and banker, one of the discoverers of Fuchsine. He wrote the first textbook on organic chemistry in the Polish language.
Life
He was born 20 August 1832 in Warsaw as th ...
in 1856 from
aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine
In organic chemistry, an aromatic amine is an organic compound consisting of an aroma ...
and
1,2-Dichloroethane
The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vinyl ...
. In 1858
August Wilhelm von Hofmann
August Wilhelm von Hofmann (8 April 18185 May 1892) was a German chemist who made considerable contributions to organic chemistry. His research on aniline helped lay the basis of the aniline-dye industry, and his research on coal tar laid the g ...
obtained it from
aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine
In organic chemistry, an aromatic amine is an organic compound consisting of an aroma ...
and
carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
. discovered the substance independently of Hofmann the same year and patented it. Fuchsine was named by its original manufacturer Renard frères et Franc, is usually cited with one of two etymologies: from the color of the flowers of the plant genus ''
Fuchsia
''Fuchsia'' () is a genus of flowering plants that consists mostly of shrubs or small trees. The first to be scientifically described, '' Fuchsia triphylla'', was discovered on the Caribbean island of Hispaniola (Haiti and the Dominican Republi ...
'',
[(2004.]
"Fuchsin"
''The American Heritage Dictionary of the English Language, Fourth Edition,'' Houghton Mifflin Company
Houghton Mifflin Harcourt (; HMH) is an American publisher of textbooks, instructional technology materials, assessments, reference works, and fiction and non-fiction for both young readers and adults. The company is based in the Boston Financ ...
, via dictionary.com. Retrieved on 2007-09-20 named in honor of botanist
Leonhart Fuchs
Leonhart Fuchs (; 17 January 1501 – 10 May 1566), sometimes spelled Leonhard Fuchs and cited in Latin as ''Leonhartus Fuchsius'', was a German physician and botanist. His chief notability is as the author of a large book about plants and th ...
, or as the German translation ''Fuchs'' of the French name Renard, which means fox. An 1861 article in ''Répertoire de Pharmacie'' said that the name was chosen for both reasons.
Acid fuchsine
Acid fuchsine
Acid fuchsin or fuchsine acid, (also called Acid Violet 19 and C.I. 42685) is an acidic magenta dye with the chemical formula C20H17N3Na2O9S3. It is a sodium sulfonate derivative of fuchsine. Acid fuchsin has wide use in histology, and is one o ...
is a mixture of homologues of basic fuchsine, modified by addition of
sulfonic groups. While this yields twelve possible isomers, all of them are satisfactory despite slight differences in their properties.
Basic fuchsine
Basic fuchsine is a mixture of rosaniline,
pararosaniline
Pararosaniline, Basic Red 9, or C.I. 42500 is an organic compound with the formula H2NC6H4)3Cl. It is a magenta solid with a variety of uses as a dye. It is one of the four components of basic fuchsine. (The others are rosaniline, new fuchsine a ...
,
new fuchsine
New fuchsine is an organic compound with the formula H2N(CH3)C6H3)3Cl. It is a green-colored solid that is used as a dye of the triarylmethane class. It is one of the four components of basic fuchsine, and one of the two that are available as ...
and
Magenta II
Magenta () is a color that is variously defined as pinkish- purplish-red, reddish-purplish-pink or mauvish- crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blue. ...
. Formulations usable for making of
Schiff reagent
:
The Schiff test is an early organic chemistry named reaction developed by Hugo Schiff, and is a relatively general chemical test for detection of many organic aldehydes that has also found use in the staining of biological tissues. The Schiff ...
must have high content of pararosanilin. The actual composition of basic fuchsine tends to somewhat vary by vendor and batch, making the batches differently suitable for different purposes.
In solution with
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
(also called carbolic acid) as an
accentuator it is called
carbol fuchsin
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 ...
and is used for the
Ziehl–Neelsen and other similar
acid-fast
Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Once stained as part of a sam ...
staining of the
mycobacteria
''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis ('' M. tuberculosis'') and ...
which cause
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
,
leprosy
Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve damag ...
etc.
[Clark G 1973 ''Staining Procedures Used by the ]Biological Stain Commission
The Biological Stain Commission (BSC) is an organization that provides third-party testing and certification of dyes and a few other compounds that are used to enhance contrast in specimens examined in biological and medical laboratories.
The BSC ...
'', 3rd ed. Baltimore: Williams & Wilkins, pp. 252–254 Basic fuchsine is widely used in biology to stain the
nucleus
Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to:
*Atomic nucleus, the very dense central region of an atom
*Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA
Nucle ...
, and is also a component of Lactofuchsin, used for
Lactofuchsin mount A Lactofuchsin mount (also spelled Lacto-fuchsin or Lacto-Fuchsin) is a technique used for mounting fungi with hyphae on a microscope slide for examination. The main advantage of a lactofuchsin mount is that if performed correctly, it preserves the ...
ing.
Properties
The crystals pictured at the right are of basic fuchsine, also known as basic violet 14, basic red 9, pararosanaline or
CI 42500. Their structure differs from the structure shown above by the absence of the
methyl group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...
on the upper ring, otherwise they are quite similar.
They are soft, with a
hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard ...
of less than 1, about the same as or less than talc. They possess a strong metallic lustre and a green yellow color. They leave dark greenish streaks on paper and when these are moistened with a solvent, the strong magenta colour appears.
Chemical structure
Fuchsine is an amine salt and has three amine groups, two
primary amines
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent s ...
and a
secondary amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such a ...
. If one of these is
protonated
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), (H+) to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, i ...
to form ABCNH
+, the positive charge is delocalized across the whole symmetrical molecule due to pi cloud electron movement.
The positive charge can be thought of as residing on the central carbon atom and all three "wings" becoming identical
aromatic ring
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturat ...
s terminated by a primary amine group. Other
resonance
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillatin ...
structures can be conceived, where the positive charge "moves" from one amine group to the next, or one third of the positive charge resides on each amine group. The ability of fuchsine to be protonated by a stronger acid gives it its
basic
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
property. The positive charge is neutralized by the negative charge on the chloride ion. The positive "basic fuchsinium ions" and negative chloride ions stack to form the salt "crystals" depicted above.
See also
*
New fuchsine
New fuchsine is an organic compound with the formula H2N(CH3)C6H3)3Cl. It is a green-colored solid that is used as a dye of the triarylmethane class. It is one of the four components of basic fuchsine, and one of the two that are available as ...
and
Acid fuchsine
Acid fuchsin or fuchsine acid, (also called Acid Violet 19 and C.I. 42685) is an acidic magenta dye with the chemical formula C20H17N3Na2O9S3. It is a sodium sulfonate derivative of fuchsine. Acid fuchsin has wide use in histology, and is one o ...
are related dyes
* Fuchsine is a component in the
Schiff test
:
The Schiff test is an early organic chemistry named reaction developed by Hugo Schiff, and is a relatively general chemical test for detection of many organic aldehydes that has also found use in the staining of biological tissues. The Schiff ...
* Fuchsine is now often used in the
Gram stain
In microbiology and bacteriology, 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. The name comes from the Danish ...
procedure in
microbiology
Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, prot ...
.
* Basic Fuchsine is a component in the
Lactofuchsin mount A Lactofuchsin mount (also spelled Lacto-fuchsin or Lacto-Fuchsin) is a technique used for mounting fungi with hyphae on a microscope slide for examination. The main advantage of a lactofuchsin mount is that if performed correctly, it preserves the ...
References
Further reading
* This provides a detailed account of early experimentation on related chemicals.
{{Stains
Triarylmethane dyes
Staining dyes
Anilines
Disinfectants
IARC Group 2B carcinogens