Immunologic tests

The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay is a solid-phase type of enzyme immunoassay (EIA) to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the ligand to be measured. ELISA has been used as a diagnostic tool in medicine, plant pathology, and biotechnology, as well as a quality control check in various industries.

annular pentameric protein found in blood plasma whose circulating concentrations rise in response to inflammation

Serology is the scientific study of antibodies in the serum and other body fluids. Such antibodies are typically formed in response to an infection (against a given microorganism), against other foreign proteins (in response, for example, to a mismatched blood transfusion), or to one's own proteins (in instances of autoimmune disease).

immunological method

An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay is often referred to as an "analyte" and is in many cases a protein, although it may be other kinds of molecules, of different sizes and types, as long as the proper antibodies that have the required properties for the assay are developed. Analytes in biological liquids such as serum or urine are frequently measured using immunoassays for medical and

thumb|230px|Main staining patterns on chromogenic immunohistochemistry. thumb|right|Immunofluorescence of human skin using an anti-IgA antibody. The skin is from a patient with [[Henoch–Schönlein purpura: IgA deposits are found in the walls of small superficial capillaries (yellow arrows). The pale wavy green area on top is the epidermis, the bottom fibrous area is the dermis.]] thumb|"Block" staining: strong nuclear and cytoplasmic expression in a continuous segment of cells. Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells

thumb|300px|Illustration showing influenza virus attaching to [[cell membrane via the surface protein hemagglutinin]] The term hemagglutinin (alternatively spelt haemagglutinin, from the Greek , 'blood' + Latin , 'glue') refers to any protein that can cause red blood cells (erythrocytes) to clump together ("agglutinate") in vitro. They do this by binding to the sugar residues on a red blood cell; when a single hemagglutinin molecule binds sugars from multiple red blood cells, it "glues" these cells together. As a result, they are carbohydrate-binding proteins (lectins). The ability to bind red

clumping of particles

thumb|278x278px|Vasculature of porcine skin under fluorescence ([[Smooth muscle actin with AlexaFluor 488). Green = smooth muscle actin (SMA) with Alexa 488 fluorophore. Blue = DAPI counterstain. Red = auto-fluorescence. ]]

immunochromatographic testing devices

A radioimmunoassay (RIA) is an immunoassay that uses radiolabeled molecules in a stepwise formation of immune complexes. A RIA is a very sensitive in vitro assay technique used to measure concentrations of substances, usually measuring antigen concentrations (for example, hormone levels in blood) by use of antibodies.

autoantibody that binds to contents of the cell nucleus

blood test used in immunohematology, application of anti-antibodies (Coombs' reagent)

allergy diagnosis

group of autoantibodies

Turbidimetry (the name being derived from turbidity) is the process of measuring the loss of intensity of transmitted light due to the scattering effect of particles suspended in it. Light is passed through a filter creating a light of known wavelength which is then passed through a cuvette containing a solution. A photoelectric cell collects the light with a spectrophotometer or a photometer, which passes through the cuvette. A measurement is then given for the amount of absorbed light.

diagnostic immunoassay using magnetic beads

Hemagglutination, or haemagglutination, is a specific form of agglutination that involves red blood cells (RBCs). It has two common uses in the laboratory: blood typing and the quantification of virus dilutions in a haemagglutination assay.

laboratory technique

medical test to determine the substance causing allergic reaction

Immunoprecipitation (IP) is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many thousands of different proteins. Immunoprecipitation requires that the antibody be coupled to a solid substrate at some point in the procedure.

thumb|right|A segment of galactomannan showing mannose backbone (below) with a branching galactose unit (top) Galactomannans are polysaccharides consisting of a mannose backbone with galactose side groups, more specifically, a (1-4)-linked beta-D-mannopyranose backbone with branchpoints from their 6-positions linked to alpha-D-galactose, (i.e. 1-6-linked alpha-D-galactopyranose).

Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin, the latter being involved with calcium homeostasis. It arises once preprocalcitonin is cleaved by endopeptidase. It was first identified by Leonard J. Deftos and Bernard A. Roos in the 1970s. It is composed of 116 amino acids and is produced by parafollicular cells (C cells) of the thyroid and by the neuroendocrine cells of the lung and the intestine.

serologic blood test based on inactivation of complement by the antigen-antibody complex (stage 1)

Titer (American English) or titre (British English) is a way of expressing concentration. Titer testing employs serial dilution to obtain approximate quantitative information from an analytical procedure that inherently only evaluates as positive or negative. The titer corresponds to the highest dilution factor that still yields a positive reading. For example, positive readings in the first 8 serial, twofold dilutions translate into a titer of 1:256 (i.e., 2−8). Titres are sometimes expressed by the denominator only, for example 1:256 is written 256.

microbiological method using antibodies

thumb|Crossed immunoelectrophoresis of 2 microlitres of normal human serum. The electrophoresis was performed in thin layers of agarose; the pictured gel is about 7x7 cm. The lower part is the first dimension gel without antibodies, where the serum was applied into the slot at the lower left. The upper part is the second dimension gel with Dako antibodies against human serum proteins. More than 50 major serum proteins can be named.

in vitro allergen radioimmunoassay in which allergens are coupled to an immunosorbent

thumb|alt=Graphical illustration of ELISpot assay|ELISpot assay illustration The enzyme-linked immunosorbent spot (ELISpot) is a type of assay that focuses on quantitatively measuring the frequency of cytokine secretion for a single cell. The ELISpot Assay is also a form of immunostaining since it is classified as a technique that uses antibodies to detect a protein analyte, with the word analyte referring to any biological or chemical substance being identified or measured.

assay for microorganisms, passive agglutination tests in which antigen is adsorbed onto latex particles which then clump in the presence of antibody

Immunodiffusion is a laboratory technique used to detect and quantify antigens and antibodies by observing their interactions within a gel medium. This technique involves the diffusion of antigens and antibodies through a gel, usually agar, resulting in the formation of a visible precipitate when they interact.

thumb|Immunolabeling - Antigen Detection of Tissue via Tagged Antigen-specific Antibody Immunolabeling is a biochemical process that enables the detection and localization of an antigen to a particular site within a cell, tissue, or organ. Antigens are organic molecules, usually proteins, capable of binding to an antibody. These antigens can be visualized using a combination of antigen-specific antibody as well as a means of detection, called a tag, that is covalently linked to the antibody. If the immunolabeling process is meant to reveal information about a cell or its substructures, the pro

biomedical technique

thumb|Immunocytochemistry labels individual proteins within cells, such as Tyrosine hydroxylase|TH (green) in the [[axons of sympathetic autonomic neurons.]]

chemical compound

test to determine susceptibility to diphtheria

medical condition

immunological method

An interferon-gamma release assay (IGRA) is a diagnostic tool for indicating a latent tuberculosis infection (LTBI). IGRAs are surrogate markers of Mycobacterium tuberculosis infection and indicate a cellular immune response to M.tuberculosis if the latter is present.

immunologic phenomenon occurring in high antigen or antibody levels

test to identify blood groups

thumb|Pipetting anti-immunoglobulins to immunofixation panel. The panel simultaneously tests 4 patients (one in each quadrant). Each patient has 6 electrophoresis panels: The left one is a conventional serum protein electrophoresis. The remainder get solutions with anti-IgG, anti-IgA, anti-IgM, anti-kappa light chain and anti-lambda light chain immunoglobulin, respectively from left to right. Each anti-immunoglobulin solution is artificially colored to ensure that the solution matches the color map at top. thumb|Immunofixation electrophoresis, schematic representation:- A. Normal serum- B. Mon

protein-coding gene in the species Homo sapiens

species of Kinetoplastea