Overview of ELISA

What does ELISA stand for?

• ELISA stands for Enzyme-Linked Immunosorbent Assay.

• ELISA stands for Enzyme-Linked Immunosorbent Analysis.

• ELISA stands for Enzyme-Linked Immunosorbent Application.

• ELISA stands for Enzyme-Linked Immunosorbent Assessment.

Which of the following is a key element of an ELISA?

• A) Antibody-antigen interaction

• B) DNA replication

• C) RNA transcription

• D) Protein synthesis

The purpose of using a microplate in an ELISA is to:

• provide a large surface area for reactions

• reduce the cost of the assay

• increase the sensitivity of the assay

• allow for easy visualization of results

What is the most commonly used enzyme in ELISA?

• The most commonly used enzyme in ELISA is horseradish peroxidase (HRP).

• Alkaline phosphatase (AP)

• Beta-galactosidase

• Glucose oxidase

Which ELISA format indirectly immobilizes and detects the presence of the target antigen?

• Direct ELISA

• Indirect ELISA

• Sandwich ELISA

• Competitive ELISA

In a sandwich ELISA, what is critical about the secondary antibody?

• It must be specific to the primary antibody

• It must be derived from the same species as the primary antibody

• It must be labeled with an enzyme or fluorophore

• It must be able to bind to the substrate

What is the purpose of using cross-adsorbed secondary antibodies in sandwich assays?

• To reduce non-specific binding

• To increase the signal strength

• To decrease the assay time

• To enhance the primary antibody binding

What is one advantage of the direct ELISA method?

• Requires more antibodies

• Quick because only one antibody and fewer steps are used

• High flexibility in choice of primary antibody label

• High signal amplification

What is a disadvantage of the indirect ELISA method?

• Cross-reactivity of secondary antibody is eliminated

• Versatile because many primary antibodies can be made in one species

• Cross-reactivity might occur with the secondary antibody, resulting in nonspecific signal

• High sensitivity and specificity

Fill in the blank: The sandwich ELISA method is highly sensitive and highly specific for target antigen as two antibodies are used for ______ and detection.

• capture

• binding

• blocking

• labeling