Question

Solid-phase immunoassays employ the property of various plastics to adsorb monomolecular layers of proteins onto their surface. Although the adsorbed molecules may lose some of their antigenic determinants, enough remain unaltered and can still react with their corresponding antibodies. What is the most common solid phase immunoassay used?

PCR
IEF
ELISA
SDS-PAGE
FACS

Answer 1

The most common solid-phase immunoassay used is the enzyme-linked immunosorbent assay (ELISA), which uses antibodies immobilized on a plastic plate to capture an antigen and detect its presence and quantity through a colorimetric reaction. Option C.

Step-by-step explanation:

The most common solid-phase immunoassay used is the enzyme-linked immunosorbent assay (ELISA). In a sandwich ELISA, antibodies are immobilized on the wells of a plastic plate. The antigen of interest is captured by the antibodies, and a colorimetric reaction is performed to detect the presence and quantity of the antigen.

In this assay, the primary antibody binds to the plastic surface, and then a second antibody conjugated to an enzyme is added. After a wash step, a colorless substrate is added, which is converted to a colored product in the presence of the enzyme.

The intensity of the color is proportional to the amount of antigen present and can be measured with a spectrophotometer. Option C.