Enzyme-linked immunosorbent assay

Enzyme-linked immunosorbent assay (ELISA), also known as an enzyme immunoassay (EIA), is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality-control check in various industries.

Principle

ELISA works by using antibodies and color change to identify a substance. ELISA tests are done to detect substances that have antigenic properties, primarily proteins (as opposed to small molecules and ions such as glucose and potassium). Some of the most common versions of the test include detection of the antibodies produced by the immune system in response to a foreign substance in the body, such as a virus or bacteria.

Procedure

The ELISA test involves several steps: coating, blocking, detection, and read-out stages. Each step requires a different set of reagents and a different amount of time to complete, depending on the specific test.

Applications

ELISA tests are commonly used in health care settings to detect various diseases, such as HIV, Lyme disease, and certain types of cancer. They are also used in food industry to detect potential food allergens, such as milk, nuts, and eggs.

Limitations

While ELISA tests are highly sensitive and specific, they can sometimes give false positive or false negative results. This can be due to a variety of factors, including cross-reactivity with other substances, improper sample handling, or technical errors in the test procedure.

See also

• Immunology
• Antibody
• Antigen
• HIV
• Lyme disease
• Cancer

References

Enzyme-linked immunosorbent assay Resources
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