Question

Antibody molecules are highly specific for their corresponding antigen. This makes antibodies valuable as probes of biological processes. Many assay techniques have been developed to take advantage of this useful property. Which of the following assays uses a pure preparation of a known antigen, antibody, or both, along with horseradish peroxidase-conjugated antibody, and is measured using spectrophotometer?

Precipitin reaction
Direct Coombs
ELISA
Radioimmunoassay
Competitive inhibition assay

Answer 1

The assay technique that employs horseradish peroxidase-conjugated antibodies and a spectrophotometer for detection is the Enzyme-linked Immunosorbent Assay (ELISA). Option C.

Step-by-step explanation:

The assay technique described in the question which uses a spectrophotometer to measure the presence and amount of antigen or antibody using a horseradish peroxidase-conjugated antibody is known as the Enzyme-linked Immunosorbent Assay (ELISA).

This method is highly specific, utilizing monoclonal or polyclonal antibodies to detect antigens.

A key feature of ELISA is its ability to provide quantitative results, which is accomplished through a color change initiated by the enzyme-substrate reaction, and the resultant color intensity is directly proportional to the amount of antigen in the sample. ELISA is extremely sensitive and can detect antigens at nanogram levels.

So Option C.