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.

Whereas a previously described LISXP-1 ELISA test had a poor sensitivity ( 55 %), the QLIPS test is both practical, as it requires only a 15 minutes incubation, and has high sensitivity and specificity ( 97 % and 100 %, respectively ).

Assessment of the A and B toxins by enzyme-linked immunosorbent assay ( ELISA ) for toxin A or B ( or both ) has a sensitivity of 63 – 99 % and a specificity of 93 – 100 %: At a prevalence of 15 %, this leads to a positive predictive value ( PPV ) of 73 % and a negative predictive value ( NPV ) of 96 %.

but no ELISA test has yet been clinically validated as a diagnostic tool.

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 ).

Today it has been supplanted by the ELISA method, where the antigen-antibody reaction is measured using colorimetric signals instead of a radioactive signal.

The antibody test ( ELISA or western blot ) uses a recombinant HIV protein to test for the presence of antibodies that the body has produced in response to an HIV infection.

More than 25 human samples have been found positive for RVF by PCR or ELISA.

In an ELISA test, a person's serum is diluted 400-fold and applied to a plate to which HIV antigens have been attached.

A range of immuno-and ligand-binding assays for the detection and measurement of small molecules such as water-soluble vitamins and chemical contaminants ( drug residues ) such as sulfonamides and Beta-agonists have been developed for use on SPR based sensor systems, often adapted from existing ELISA or other immunological assay.

Enzyme linked immunosorbent assay ( ELISA ), PCR, and sequence technology tests have been developed.

For example, donors are tested for HIV by ELISA, which shows if they have been exposed to the disease, as well as by nucleic acid methods ( PCR or similar ) to rule out recent infections that the ELISA test might miss.

ELISA and microagglutination tests have also been successfully applied.

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.

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.

ELISA can also be used in toxicology as a rapid presumptive screen for certain classes of drugs.

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

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

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

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.

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.

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.

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.

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

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.

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.

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.

There are a number of diagnostic tests for including: HCV antibody enzyme immunoassay or ELISA, recombinant immunoblot assay, and quantitative HCV RNA polymerase chain reaction ( PCR ).

When the ELISA test is combined with Western Blot, the rate of false positives is extremely low, and diagnostic accuracy is very high ( see below ).

The enzyme-linked immunosorbent assay or ELISA is a diagnostic method for quantitatively or semi-quantitatively determining protein concentrations from blood plasma, serum or cell / tissue extracts in a multi-well plate format ( usually 96-wells per plate ).

A very common usage is in the enzyme-linked immunosorbent assay ( ELISA ), the basis of most modern medical diagnostic testing in humans and animals.

Molecular diagnostic techniques for the detection of phytoplasma began to emerge in the 1980s and included ELISA based methods.

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.

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 ).

* Novel ELISPOT Chambered slide provides a convenient, cost-effective slide based ELISA tool.