Enzyme immunoassay

Enzyme Immunoassay (EIA) is a biochemical technique used in immunology. The EIA technique is primarily used for detecting the presence of an antibody or an antigen in a sample. The EIA technique is a popular choice in many laboratories, including those that study plant pathology, veterinary medicine, and biomedicine.

Overview

The EIA technique is based on the principle of antigen-antibody interaction. The antigen-antibody interaction is a specific chemical interaction between antibodies produced by B cells of the white blood cells and antigens during immune reaction. The EIA technique uses enzymes as labels to detect the presence of the target molecule.

Procedure

The EIA procedure involves the following steps:

1. Coating: The first step in the EIA procedure is coating the surface of a microtiter plate with a capture antibody. This antibody is specific to the target antigen.
2. Blocking: The next step is blocking. This step prevents non-specific binding of other proteins to the capture antibody.
3. Addition of Antigen: The antigen sample is then added to the plate. If the antigen is present in the sample, it will bind to the capture antibody.
4. Addition of Detection Antibody: A detection antibody is then added. This antibody is also specific to the target antigen, but it is linked to an enzyme.
5. Addition of Substrate: A substrate is then added. The enzyme linked to the detection antibody will react with the substrate, producing a color change.
6. Reading the Plate: The plate is then read on a spectrophotometer. The intensity of the color change is proportional to the amount of antigen present in the sample.

Applications

The EIA technique has a wide range of applications in various fields. Some of the applications of the EIA technique include:

• Disease Diagnosis: The EIA technique is used for the diagnosis of various diseases, including infectious diseases, autoimmune diseases, and allergies.
• Food Testing: The EIA technique is used for testing food samples for the presence of allergens, toxins, and other contaminants.
• Drug Testing: The EIA technique is used for drug testing in sports and workplaces.
• Environmental Monitoring: The EIA technique is used for monitoring environmental pollutants.

See Also

• Immunoassay
• Antibody
• Antigen
• Enzyme