TMFS

Which of the following ELISA types involves the use of two antibodies that bind to different epitopes on the same antigen?

• Direct ELISA

• Indirect ELISA

• Sandwich ELISA

• Competitive ELISA

In which type of ELISA is the antigen and labeled antigen made to compete for the same antibody binding site?

• Sandwich ELISA

• Direct ELISA

• Competitive ELISA

• Indirect ELISA

Which ELISA type is best suited for detecting antibodies rather than antigens?

• Indirect ELISA

• Competitive ELISA

• Direct ELISA

• Sandwich ELISA

In a direct ELISA, the enzyme is linked to which of the following?

• Secondary antibody

• Antigen

• Substrate

• Primary antibody

Which ELISA format is most likely to give a false negative if the sample has very low antigen concentration?

• Indirect ELISA

• Sandwich ELISA

• Direct ELISA

• Competitive ELISA

Assertion (A): In direct ELISA, multiple amplification steps are involved for signal generation.
Reason (R): Direct ELISA uses a primary antibody that is enzyme-labeled.

• Both A and R are true, and R is the correct explanation of A

• Both A and R are true, but R is not the correct explanation of A

• A is false, but R is true

• Both A and R are false

________ ELISA uses a secondary antibody for detection, which binds to the primary antibody specific to the antigen.

In ________ ELISA, the intensity of the color is inversely proportional to the amount of antigen present in the sample.

The substrate used in ELISA reacts with the enzyme to produce a visible color change; for example, ________ is a common chromogenic substrate for HRP.

he purpose of the washing steps in ELISA is to remove ________ antibodies/antigens.