Enzyme-linked immunosorbent assays (ELISAs)

Definition

Enzyme-linked immunosorbent assays (ELISAs) are laboratory techniques used to detect and quantify substances such as proteins, antibodies, and hormones. They rely on enzyme-mediated color changes to indicate the presence of a target molecule.

5 Must Know Facts For Your Next Test

1. ELISAs use an enzyme linked to an antibody or antigen as a marker for detection.
2. There are four main types of ELISAs: direct, indirect, sandwich, and competitive.
3. Color change in an ELISA indicates the presence of the target substance due to enzyme-substrate reactions.
4. ELISAs are highly sensitive and can detect minute amounts of a substance in a sample.
5. Blocking agents are often used to prevent non-specific binding in ELISA procedures.

Review Questions

• What is the main purpose of using an enzyme in an ELISA?
• Name and briefly describe one type of ELISA.
• Why are blocking agents important in ELISA protocols?

Related terms

Antigen: A molecule capable of inducing an immune response.

Antibody: A protein produced by the immune system that specifically binds to a particular antigen.

Immunoassay: A biochemical test that measures the presence or concentration of a substance using an antibody or antigen.