HOME

TheInfoList



OR:

Histology, also known as microscopic anatomy or microanatomy, is the branch of
biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary ...
which studies the microscopic
anatomy Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...
of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and ''
cytology Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...
'', the study of
cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
, modern usage places all of these topics under the field of histology. In medicine,
histopathology Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Spec ...
is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms.


Biological tissues


Animal tissue classification

There are four basic types of animal tissues: muscle tissue,
nervous tissue Nervous tissue, also called neural tissue, is the main tissue component of the nervous system. The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the bra ...
, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types (for example, blood is classified as connective tissue, since the blood cells are suspended in an extracellular matrix, the plasma).


Plant tissue classification

For plants, the study of their tissues falls under the field of
plant anatomy Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. Originally it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century plant ...
, with the following four main types: * Dermal tissue *
Vascular tissue Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There ...
*
Ground tissue The ground tissue of plants includes all tissues that are neither dermal nor vascular. It can be divided into three types based on the nature of the cell walls. # Parenchyma cells have thin primary walls and usually remain alive after they beco ...
*
Meristematic tissue The meristem is a type of tissue found in plants. It consists of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells conti ...


Medical histology

Histopathology Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Spec ...
is the branch of histology that includes the microscopic identification and study of diseased tissue. It is an important part of
anatomical pathology Anatomical pathology (''Commonwealth'') or Anatomic pathology (''U.S.'') is a medical specialty that is concerned with the diagnosis of disease based on the macroscopic, microscopic, biochemical, immunologic and molecular examination ...
and
surgical pathology Surgical pathology is the most significant and time-consuming area of practice for most anatomical pathologists. Surgical pathology involves gross and microscopic examination of surgical specimens, as well as biopsies submitted by surgeons and ...
, as accurate diagnosis of cancer and other diseases often requires histopathological examination of tissue samples. Trained physicians, frequently licensed
pathologist Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in th ...
s, perform histopathological examination and provide diagnostic information based on their observations.


Occupations

The field of histology that includes the preparation of tissues for microscopic examination is known as histotechnology. Job titles for the trained personnel who prepare histological specimens for examination are numerous and include histotechnicians, histotechnologists, histology technicians and technologists, medical laboratory technicians, and
biomedical scientist A biomedical scientist is a scientist trained in biology, particularly in the context of medical laboratory sciences or laboratory medicine. These scientists work to gain knowledge on the main principles of how the human body works and to find new w ...
s.


Sample preparation

Most histological samples need preparation before microscopic observation; these methods depend on the specimen and method of observation.


Fixation

Chemical fixatives are used to preserve and maintain the structure of tissues and cells; fixation also hardens tissues which aids in cutting the thin sections of tissue needed for observation under the microscope. Fixatives generally preserve tissues (and cells) by irreversibly cross-linking proteins. The most widely used fixative for light microscopy is 10% neutral buffered
formalin Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section F ...
, or NBF (4% formaldehyde in phosphate buffered saline). For electron microscopy, the most commonly used fixative is
glutaraldehyde Glutaraldehyde is an organic compound with the formula . The molecule consists of a five carbon chain doubly terminated with formyl (CHO) groups. It is usually used as a solution in water, and such solutions exists as a collection of hydrates, c ...
, usually as a 2.5% solution in phosphate buffered saline. Other fixatives used for electron microscopy are osmium tetroxide or
uranyl acetate Uranyl acetate is the acetate salt of uranium oxide, a toxic yellow-green powder useful in certain laboratory tests. Structurally, it is a coordination polymer with formula UO2(CH3CO2)2(H2O)·H2O. Structure In the polymer, uranyl (UO22+) c ...
. The main action of these
aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group ...
fixatives is to cross-link amino groups in proteins through the formation of methylene bridges (-CH2-), in the case of formaldehyde, or by C5H10 cross-links in the case of glutaraldehyde. This process, while preserving the structural integrity of the cells and tissue can damage the biological functionality of proteins, particularly
enzymes Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...
. Formalin fixation leads to degradation of mRNA, miRNA, and DNA as well as denaturation and modification of proteins in tissues. However, extraction and analysis of nucleic acids and proteins from formalin-fixed, paraffin-embedded tissues is possible using appropriate protocols.


Selection and trimming

''Selection'' is the choice of relevant tissue in cases where it is not necessary to put the entire original tissue mass through further processing. The remainder may remain fixated in case it needs to be examined at a later time. ''Trimming'' is the cutting of tissue samples in order to expose the relevant surfaces for later sectioning. It also creates tissue samples of appropriate size to fit into cassettes.


Embedding

Tissues are embedded in a harder medium both as a support and to allow the cutting of thin tissue slices. In general, water must first be removed from tissues (dehydration) and replaced with a medium that either solidifies directly, or with an intermediary fluid (clearing) that is miscible with the embedding media.


Paraffin wax

For light microscopy, paraffin wax is the most frequently used embedding material. Paraffin is immiscible with water, the main constituent of biological tissue, so it must first be removed in a series of dehydration steps. Samples are transferred through a series of progressively more concentrated ethanol baths, up to 100% ethanol to remove remaining traces of water. Dehydration is followed by a ''clearing agent'' (typically
xylene In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are su ...
although other environmental safe substitutes are in use) which removes the alcohol and is miscible with the wax, finally melted paraffin wax is added to replace the xylene and infiltrate the tissue. In most histology, or histopathology laboratories the dehydration, clearing, and wax infiltration are carried out in ''tissue processors'' which automate this process. Once infiltrated in paraffin, tissues are oriented in molds which are filled with wax; once positioned, the wax is cooled, solidifying the block and tissue.


Other materials

Paraffin wax does not always provide a sufficiently hard matrix for cutting very thin sections (which are especially important for electron microscopy). Paraffin wax may also be too soft in relation to the tissue, the heat of the melted wax may alter the tissue in undesirable ways, or the dehydrating or clearing chemicals may harm the tissue. Alternatives to paraffin wax include, epoxy,
acrylic Acrylic may refer to: Chemicals and materials * Acrylic acid, the simplest acrylic compound * Acrylate polymer, a group of polymers (plastics) noted for transparency and elasticity * Acrylic resin, a group of related thermoplastic or thermosett ...
,
agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori ('' Gracilaria'') and "tengusa" ('' Gelidiaceae''). As found in nature, agar ...
,
gelatin Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also ...
, celloidin, and other types of waxes. In electron microscopy epoxy resins are the most commonly employed embedding media, but acrylic resins are also used, particularly where
immunohistochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to ant ...
is required. For tissues to be cut in a frozen state, tissues are placed in a water-based embedding medium. Pre-frozen tissues are placed into molds with the liquid embedding material, usually a water-based glycol, OCT, TBS, Cryogen, or resin, which is then frozen to form hardened blocks.


Sectioning

For light microscopy, a knife mounted in a microtome is used to cut tissue sections (typically between 5-15
micrometers The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer ( American spelling), also commonly known as a micron, is a unit of length in the International System of Uni ...
thick) which are mounted on a glass
microscope slide A microscope slide is a thin flat piece of glass, typically 75 by 26 mm (3 by 1 inches) and about 1 mm thick, used to hold objects for examination under a microscope. Typically the object is mounted (secured) on the slide, and then ...
. For transmission electron microscopy (TEM), a diamond or glass knife mounted in an
ultramicrotome A microtome (from the Greek ''mikros'', meaning "small", and ''temnein'', meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as ''sections''. Important in science, microtomes are used in microscopy, allow ...
is used to cut between 50 and 150 nanometer thick tissue sections.


Staining

Biological tissue has little inherent contrast in either the light or electron microscope.
Staining Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the ...
is employed to give both contrast to the tissue as well as highlighting particular features of interest. When the stain is used to target a specific chemical component of the tissue (and not the general structure), the term
histochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to ant ...
is used.


Light microscopy

Hematoxylin and eosin (
H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagn ...
) is one of the most commonly used stains in histology to show the general structure of the tissue. Hematoxylin stains cell nuclei blue; eosin, an
acidic In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
dye, stains the
cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...
and other tissues in different stains of pink. In contrast to H&E, which is used as a general stain, there are many techniques that more selectively stain cells, cellular components, and specific substances. A commonly performed histochemical technique that targets a specific chemical is the Perls' Prussian blue reaction, used to demonstrate iron deposits in diseases like hemochromatosis. The
Nissl method Franz Alexander Nissl (9 September 1860, in Frankenthal – 11 August 1919, in Munich) was a German psychiatrist and medical researcher. He was a noted neuropathologist. Early life Nissl was born in Frankenthal to Theodor Nissl and Maria Haas. ...
for Nissl substance and Golgi's method (and related
silver stains In pathology, silver staining is the use of silver to selectively alter the appearance of a target in microscopy of histological sections; in temperature gradient gel electrophoresis; and in polyacrylamide gels. In traditional stained glass, silve ...
) are useful in identifying neurons are other examples of more specific stains.


Historadiography

In
historadiography Historadiography is a technique formerly utilized in the fields of histology and cellular biology to provide semiquantitative information regarding the density of a tissue sample. It is usually synonymous with microradiography. This is achieved by ...
, a slide (sometimes stained histochemically) is X-rayed. More commonly,
autoradiography An autoradiograph is an image on an X-ray film or nuclear emulsion produced by the pattern of decay emissions (e.g., beta particles or gamma rays) from a distribution of a radioactive substance. Alternatively, the autoradiograph is also availab ...
is used in visualizing the locations to which a radioactive substance has been transported within the body, such as cells in S phase (undergoing DNA replication) which incorporate tritiated
thymidine Thymidine (symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. ...
, or sites to which radiolabeled nucleic acid probes bind in
in situ hybridization ''In situ'' hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue (''in situ'') or ...
. For autoradiography on a microscopic level, the slide is typically dipped into liquid nuclear tract emulsion, which dries to form the exposure film. Individual silver grains in the film are visualized with
dark field microscopy Dark-field microscopy (also called dark-ground microscopy) describes microscopy methods, in both light and electron microscopy, which exclude the unscattered beam from the image. As a result, the field around the specimen (i.e., where there is ...
.


Immunohistochemistry

Recently,
antibodies An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
have been used to specifically visualize proteins, carbohydrates, and lipids. This process is called
immunohistochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to ant ...
, or when the stain is a
fluorescent Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...
molecule,
immunofluorescence Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specifi ...
. This technique has greatly increased the ability to identify categories of cells under a microscope. Other advanced techniques, such as nonradioactive ''in situ'' hybridization, can be combined with immunochemistry to identify specific DNA or RNA molecules with fluorescent probes or tags that can be used for immunofluorescence and enzyme-linked fluorescence amplification (especially
alkaline phosphatase The enzyme alkaline phosphatase (EC 3.1.3.1, alkaline phosphomonoesterase; phosphomonoesterase; glycerophosphatase; alkaline phosphohydrolase; alkaline phenyl phosphatase; orthophosphoric-monoester phosphohydrolase (alkaline optimum), systematic ...
and tyramide signal amplification). Fluorescence microscopy and
confocal microscopy Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a ...
are used to detect fluorescent signals with good intracellular detail.


Electron microscopy

For electron microscopy
heavy metals upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...
are typically used to stain tissue sections.
Uranyl acetate Uranyl acetate is the acetate salt of uranium oxide, a toxic yellow-green powder useful in certain laboratory tests. Structurally, it is a coordination polymer with formula UO2(CH3CO2)2(H2O)·H2O. Structure In the polymer, uranyl (UO22+) c ...
and lead citrate are commonly used to impart contrast to tissue in the electron microscope.


Specialized techniques


Cryosectioning

Similar to the
frozen section procedure The frozen section procedure is a pathological laboratory procedure to perform rapid microscopic analysis of a specimen. It is used most often in oncological surgery. The technical name for this procedure is cryosection. The microtome device that ...
employed in medicine, cryosectioning is a method to rapidly freeze, cut, and mount sections of tissue for histology. The tissue is usually sectioned on a cryostat or freezing microtome. The frozen sections are mounted on a glass slide and may be stained to enhance the contrast between different tissues. Unfixed frozen sections can be used for studies requiring enzyme localization in tissues and cells. Tissue fixation is required for certain procedures such as antibody-linked
immunofluorescence Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specifi ...
staining. Frozen sections are often prepared during surgical removal of tumors to allow rapid identification of tumor margins, as in Mohs surgery, or determination of tumor malignancy, when a tumor is discovered incidentally during surgery.


Ultramicrotomy

Ultramicrotomy is a method of preparing extremely thin sections for transmission electron microscope (TEM) analysis. Tissues are commonly embedded in epoxy or other plastic resin. Very thin sections (less than 0.1 micrometer in thickness) are cut using diamond or glass knives on an
ultramicrotome A microtome (from the Greek ''mikros'', meaning "small", and ''temnein'', meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as ''sections''. Important in science, microtomes are used in microscopy, allow ...
.


Artifacts

Artifacts are structures or features in tissue that interfere with normal histological examination. Artifacts interfere with histology by changing the tissues appearance and hiding structures. Tissue processing artifacts can include pigments formed by fixatives, shrinkage, washing out of cellular components, color changes in different tissues types and alterations of the structures in the tissue. An example is mercury pigment left behind after using
Zenker's fixative Zenker's fixative is a rapid-acting fixative for animal tissues. It is employed to prepare specimens of animal or vegetable tissues for microscopic study. It provides excellent fixation of nuclear chromatin, connective tissue fibers and some cytop ...
to fix a section. Formalin fixation can also leave a brown to black pigment under acidic conditions.


History

In the 17th century the Italian
Marcello Malpighi Marcello Malpighi (10 March 1628 – 30 November 1694) was an Italian biologist and physician, who is referred to as the "Founder of microscopical anatomy, histology & Father of physiology and embryology". Malpighi's name is borne by several ph ...
used microscopes to study tiny biological entities; some regard him as the founder of the fields of histology and microscopic pathology. Malpighi analyzed several parts of the organs of bats, frogs and other animals under the microscope. While studying the structure of the lung, Malpighi noticed its membranous alveoli and the hair-like connections between veins and arteries, which he named capillaries. His discovery established how the oxygen breathed in enters the blood stream and serves the body. In the 19th century histology was an academic discipline in its own right. The French anatomist
Xavier Bichat Marie François Xavier Bichat (; ; 14 November 1771 – 22 July 1802) was a French anatomist and pathologist, known as the father of modern histology. Although he worked without a microscope, Bichat distinguished 21 types of elementary tissue ...
introduced the concept of tissue in anatomy in 1801, and the term "histology" ( de , Histologie), coined to denote the "study of tissues", first appeared in a book by Karl Meyer in 1819. Bichat described twenty-one human tissues, which can be subsumed under the four categories currently accepted by histologists. The usage of illustrations in histology, deemed as useless by Bichat, was promoted by
Jean Cruveilhier Jean Cruveilhier (; 9 February 1791 – 7 March 1874) was a French anatomist and pathologist. Academic career Cruveilhier was born in Limoges, France. As a student in Limoges, he planned to enter the priesthood. He later developed an inte ...
. In the early 1830s Purkynĕ invented a microtome with high precision. During the 19th century many fixation techniques were developed by
Adolph Hannover Adolph Hannover (24 November 1814 - 7 July 1894) was a Danish pathologist who in 1843 carried out the first definitive microscopic description of a cancer cell. Hannover is said to have introduced the microscope to Denmark, but his work had wides ...
(solutions of
chromate Chromate or chromat, and their derived terms, may refer to: Chemistry * Chromate and dichromate, ions * Monochromate, an ion * Trichromate, an ion * Tetrachromate, an ion * Chromate conversion coating, a method for passivating metals Biology ...
s and
chromic acid The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. This kind of chromic acid may be used as a cleaning mixtu ...
), Franz Schulze and Max Schultze (
osmic acid Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO4. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of unusual properties, one being that the ...
), Alexander Butlerov ( formaldehyde) and
Benedikt Stilling Benedikt Stilling (11 February 1810 – 28 January 1879) was a German anatomist and surgeon who was a native of Kirchhain. He was the father of German ophthalmologist Jakob Stilling (1842–1915). In 1832 he received his doctorate from the Univ ...
(
freezing Freezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point. In accordance with the internationally established definition, freezing means the solidification phase change of a liquid o ...
). Mounting techniques were developed by
Rudolf Heidenhain Rudolf Peter Heinrich Heidenhain (; 29 January 1834 – 13 October 1897) was a German physiologist born in Marienwerder, East Prussia (now Kwidzyn, Poland). His son, Martin Heidenhain, was a highly regarded anatomist. Academic career He studi ...
(1824-1898), who introduced gum Arabic;
Salomon Stricker Salomon Stricker (1 January 1834 – 2 April 1898) was an Austrian pathologist and histologist. Career Stricker was born in Waag-Neustadtl (Hungarian: Vágújhely, now Nové Mesto nad Váhom in Slovakia). He studied at the University of Vienna, ...
(1834-1898), who advocated a mixture of wax and oil; and
Andrew Pritchard Andrew Pritchard FRSE (14 December 1804 – 24 November 1882) was an English naturalist and natural history dealer who made significant improvements to microscopy and studied microscopic organisms. His belief that God and nature were one led hi ...
(1804-1884) who, in 1832, used a gum/ isinglass mixture. In the same year, Canada balsam appeared on the scene, and in 1869
Edwin Klebs Theodor Albrecht Edwin Klebs (6 February 1834 – 23 October 1913) was a German-Swiss microbiologist. He is mainly known for his work on infectious diseases. His works paved the way for the beginning of modern bacteriology, and inspired Louis ...
(1834-1913) reported that he had for some years embedded his specimens in paraffin. The 1906 Nobel Prize in Physiology or Medicine was awarded to histologists Camillo Golgi and
Santiago Ramon y Cajal Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...
. They had conflicting interpretations of the neural structure of the brain based on differing interpretations of the same images. Ramón y Cajal won the prize for his correct theory, and Golgi for the silver-staining
technique Technique or techniques may refer to: Music * The Techniques, a Jamaican rocksteady vocal group of the 1960s *Technique (band), a British female synth pop band in the 1990s * ''Technique'' (album), by New Order, 1989 * ''Techniques'' (album), by M ...
that he invented to make it possible.


Future directions


''In vivo'' histology

Currently there is intense interest in developing techniques for ''in vivo'' histology (predominantly using
MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
), which would enable doctors to non-invasively gather information about healthy and diseased tissues in living patients, rather than from fixed tissue samples.


Notes


References


External links

* {{Authority control Histotechnology Staining Histochemistry Anatomy