FACTOID # 22: South Dakota has the highest employment ratio in America, but the lowest median earnings of full-time male employees.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Immunoassay" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Immunoassay

An immunoassay is a biochemical test that measures the concentration of a substance in a biological liquid, typically serum or urine, using the reaction of an antibody or antibodies to its antigen. The assay takes advantage of the specific binding of an antibody to its antigen. Monoclonal antibodies are often used as they only usually bind to one site of a particular molecule, and therefore provide a more specific and accurate test, which is less easily confused by the presence of other molecules. The antibodies picked must have a high affinity for the antigen (if there is antigen available, a very high proportion of it must bind to the antibody). Biochemistry is the chemistry of life. ... In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. ... Blood plasma is the liquid component of blood, in which the blood cells are suspended. ... This article or section is in need of attention from an expert on the subject. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... An assay is a procedure where the concentration of a component part of a mixture is determined. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... // Monoclonal antibodies (mAb) are antibodies that are identical because they were produced by one type of immune cell and are all clones of a single parent cell. ... Wikipedia does not yet have an article with this exact name. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ...


Both the presence of antigen or antibodies can be measured. For instance, when detecting infection the presence of antibody against the pathogen is measured. For measuring hormones such as insulin, the insulin acts as the antigen. This article does not cite any references or sources. ... Wikipedia does not yet have an article with this exact name. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... A pathogen or infectious agent is a biological agent that causes disease or illness to its host. ... Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... Insulin (from Latin insula, island, as it is produced in the Islets of Langerhans in the pancreas) is an anabolic polypeptide hormone that regulates carbohydrate metabolism. ... Insulin (from Latin insula, island, as it is produced in the Islets of Langerhans in the pancreas) is an anabolic polypeptide hormone that regulates carbohydrate metabolism. ... This article does not cite any references or sources. ...


For numerical results, the response of the fluid being measured must be compared to standards of a known concentration. This is usually done though the plotting of a standard curve on a graph, the position of the curve at response of the unknown is then examined, and so the quantity of the unknown found.


Detecting the quantity of antibody or antigen can be achieved by a variety of methods. One of the most common is to label either the antigen or antibody. The label may consist of an enzyme (see enzyme immunoassay (EIA)), radioisotopes such as I-125 Radioimmunoassay (RIA) or fluorescence. Other techniques include agglutination, nephelometry, turbidimetry and Western Blot. Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... An immunoassay is a biochemical test that measures the level of bodily reaction to a foreign object. ... A radionuclide is an atom with an unstable nucleus. ... Radioimmunoassay is a scientific method used to test hormone levels in the blood without the need to use a bioassay. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... agglutination ... Nephelometry is a technique used in immunology to determine levels of IgM, IgG, and IgA.[1] It is performed by shining light on a sample, and measuring the amount of light reflected. ... Figure 1. ...


Immunoassays have a particularly important role in the diagnosis of HIV through the HIV test Species Human immunodeficiency virus 1 Human immunodeficiency virus 2 Human immunodeficiency virus (HIV) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS, a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections). ... Randal Tobias, U.S. Global AIDS Coordinator, being publicly tested for HIV/AIDS in Ethiopia in an effort to reduce the stigma of being tested. ...


Types

Immunoassays can be divided into those that involve labelled reagents and those which involve non-labelled reagents. Those which involve labelled reagents are divided into homogenous and heterogenous (which involved a separation step) immunoassays. Heterogenous immunoassays can be competitive or non-competitive.

  • In a competitive immunoassay, the antigen in the unknown sample competes with labeled antigen to bind with antibodies. The amount of labeled antigen bound to the antibody site is then measured. In this method, the response will be inversely proportional to the concentration of antigen in the unknown. This is because the greater the response, the less antigen in the unknown was available to compete with the labeled antigen.
  • In noncompetitive immunoassays, also referred to as the "sandwich assay," antigen in the unknown is bound to the antibody site, then labeled antibody is bound to the antigen. The amount of labeled antibody on the site is then measured. Unlike the competitive method, the results of the noncompetitive method will be directly proportional to the concentration of the antigen. This is because labeled antibody will not bind if the antigen is not present in the unknown sample.

Immunoassays can be homogeneous or heterogeneous: This article does not cite any references or sources. ... This article does not cite any references or sources. ... Wikipedia does not yet have an article with this exact name. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ...

  • A heterogeneous immunoassay will require an extra step to remove unbound antibody or antigen from the site, usually using a solid phase reagent.
  • Because homogeneous assays do not require this step, they are typically faster and easier to perform.

Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... This article does not cite any references or sources. ... An assay is a procedure for the determination of the concentration of a particular constituent of a mixture. ...

See also

  • Immunofluorescent antibody analysis

External links


  Results from FactBites:
 
Food Safety Research Information Office: A Focus on Bovine Spongiform Encephalopathy (4562 words)
Using non-invasive technology, identify in viva diagnostic and prion disease progression markers using magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) in humans and animal models.
Improve and validate an existing fluorescent immunoassay method, used in sheep blood analysis, for application in bovine and human prion diseases using blood, cerebrospinal fluid, and urine analysis.
Improved methods must enable detection of PrPsc in the early stages of disease, prior to clinical symptoms.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m