Researchers at Ben Gurion University in Israel are developing a different device called the BioPen, essentially a " Lab-in-a-Pen ", which can detect known biological agents in under 20 minutes using an adaptation of the ELISA, a similar widely employed immunological technique, that in this case incorporates fiber optics.

Of note, ELISA can perform other forms of ligand binding assays instead of strictly " immuno " assays, though the name carried the original " immuno " because of the common use and history of development of this method.

Unlike other spectrophotometric wet lab assay formats where the same reaction well ( e. g. a cuvette ) can be reused after washing, the ELISA plates have the reaction products immunosorbed on the solid phase which is part of the plate, so are not easily reusable.

As a " wet lab " analytic biochemistry assay, ELISA involves detection of an " analyte " ( i. e. the specific substance whose presence is being quantitatively or qualitatively analyzed ) in a liquid sample by a method that continues to use liquid reagents during the " analysis " ( i. e. controlled sequence of biochemical reactions that will generate a signal which can be easily quantified and interpreted as a measure of the amount of analyte in the sample ) that stays liquid and remains inside a reaction chamber or well needed to keep the reactants contained ; It is opposed to " dry lab " that can use dry strips-and even if the sample is liquid ( e. g. a measured small drop ), the final detection step in " dry " analysis involves reading of a dried strip by methods such as reflectometry and does not need a reaction containment chamber to prevent spillover or mixing between samples.

The ligand-specific binding reagent is " immobilized ", i. e., usually coated and dried onto the transparent bottom and sometimes also side wall of a well ( the stationary " solid phase '/" solid substrate " here as opposed to solid microparticle / beads that can be washed away ), which is usually constructed as a multiple-well plate known as the " ELISA plate ".

A descriptive animation of the application of sandwich ELISA to home pregnancy testing can be found here.

Because the ELISA can be performed to evaluate either the presence of antigen or the presence of antibody in a sample, it is a useful tool for determining serum antibody concentrations ( such as with the HIV test or West Nile virus ).

They state that this can be reliably used to analyze the amylase levels and is definitely a cheaper alternative as compared to the more expensive ELISA kits.

As with the ELISPOT and ELISA procedures, the enzyme can be provided with a substrate molecule that will be converted by the enzyme to a colored reaction product that will be visible on the membrane ( see the figure below with blue bands ).

Histology of tissues will show accumulation of prion in the central nervous system, and immunohistochemical staining and ELISA can also be used to demonstrate the protein.

These can be detected using an enzyme-linked immunosorbent assay ( ELISA ) immunological test, which screens for the presence of β < sub > 2 </ sub > glycoprotein 1 dependent anticardiolipin antibodies ( ACA ).

ELISA kits can be used to examine up and down regulation of proinflammatory mediators such as cytokines ( IL-1, TNF alpha, PGE2 )....

ELISA or RIA can also be used.

The syphilis anti-cardiolipin antibodies are beta-2 glycoprotein independent, whereas those that occur in the antiphospholipid antibody syndrome ( associated to lupus for example ) are beta-2 glycoprotein dependent, and this can be used to tell them apart in an ELISA assay.

It can also be diagnosed by detection of antigens in blood or urine samples by ELISA or PCR.

Serological testing is most commonly performed with an ELISA or complement fixation, and viral isolation can also be attempted.

This can be useful in subcellular localization, ELISA, western blotting or other immuno-analytical methods.

Quantification of viral load can be determined by Plaque Assay, antigen capture enzyme immunoassay ( EIA ), ELISA and HA, and quantification of antibody levels by HAI and Neutralisation assay.

Epitopes can be mapped using protein microarrays, and with the ELISPOT or ELISA techniques.

A wide range of cellular secretions ( say, a specific antibody or cytokine ) can be detected using the ELISA technique.

If antibodies against the protein are available then western blotting and ELISA can specifically detect and quantify the amount of desired protein.

The ELISA ( enzyme-linked immunosorbent assay ) test can be the first step in non-culture methods of identifying P. ramorum, but it can only be a first step, because it detects the presence of proteins that are produced by all Phytophthora species.

The analyte is also called the ligand because it will specifically bind or ligate to a detection reagent, thus ELISA falls under the bigger category of ligand binding assays.

ELISA tests also are used as in in vitro diagnostics in medical laboratories.

There is also a urine ELISA test with a 96 % sensitivity and 79 % specificity.

ELISA and microagglutination tests have also been successfully applied.

Serological testing such as enzyme-linked immunosorbent assay ( ELISA ) or the Western blot are also reliable but may not be easily accessible in endemic areas.

Therefore, immunonological methods such ELISA and enzyme-linked immunoelectrotransfer blot, also called Western blot, are the most important methods in diagnosis of F. hepatica infection.

The ELISA test, however, detects all circulating antibodies that bind heparin-PF4 complexes, and may also falsely identify antibodies that do not cause HIT.

Anti-desmoglein antibodies can also be detected in a blood sample using the ELISA technique.

* ELBA, or enzyme-linked binding assay ( see also ELISA )

Serological testing can also be performed with an ELISA.

The bacterium can be isolated from various body fluids, and serological testing with an ELISA can also be performed.

The early 1980s also saw the development at USAMRIID of new diagnostic methods for several pathogenic organisms such as ELISA technology and the extensive use of monoclonal antibodies.

When using the blood sera of wild birds and sentinel chickens, samples must be tested for the presence of WNV antibodies by use of immunohistochemistry ( IHC ) or Enzyme-Linked Immunosorbent Assay ( ELISA ).

ELISA may be run in a qualitative or quantitative format.

If an ELISA test is used for drug screening at workplace, a cut-off concentration, 50 ng / ml, for example, is established, and a sample containing the standard concentration of analyte will be prepared.

ELISA testing alone cannot be used to diagnose HIV, even if the test suggests a high probability that antibody to HIV-1 is present.

Antibody presence in blood serum is often used to determine whether a person has been exposed to a given virus in the past, with tests such as ELISA.

Other techniques used include direct fecal smears, culturing fecal samples on agar plates, serodiagnosis through ELISA, and duodenal fumigation.

For cystic echinococcosis, imaging is the main method that is relied on for diagnosis while serology tests ( such as indirect hemogglutination, ELISA ( enzyme linked immunosorbent assay ), immunoblots or latex agglutination ) that use antigens specific for E. granulosus are used to verify the imaging results.

The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality-control check in various industries.

A major disadvantage of the indirect ELISA is the method of antigen immobilization is not specific ; when serum is used as the source of test antigen, all proteins in the sample may stick to the microtiter plate well, so small concentrations of analyte in serum must compete with other serum proteins when binding to the well surface.

A less-common variant of this technique, a " sandwich " ELISA, is used to detect sample antigen.

The ELISA was the first screening test widely used for HIV because of its high sensitivity.

* " Introduction to ELISA Activity-beginner walkthrough of ELISA used for detecting HIV, including animations at University of Arizona

In the 1970s, the discovery of monoclonal antibodies led to the development of the relatively simple and cheap immunoassays, such as agglutination-inhibition-based assays and sandwich ELISA, used in modern home pregnancy tests.

A 96-well microtiter plate being used for ELISA.

While AIDS denialists focus on individual components of HIV testing, the combination of ELISA and Western blot used for the diagnosis of HIV is remarkably accurate, with very low false-positive and-negative rates as described above.

Absorbance detection has been available in microplate readers for more than 3 decades, and is used for assays such as ELISA assays, protein and nucleic acid quantification or enzyme activity assays ( i. e. in the MTT assay for cell viability ).

PCR, ELISA, and serological testing are more commonly used to diagnose Toxocara infection.

Other techniques used in the analysis of lipid rafts include ELISA, western blotting, and FACS.

Rhodamine dyes are used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA.