Which assay does not rely on a limited-binding macromolecule principle?

Which assay does not rely on a limited-binding macromolecule principle?

• A. Chemiluminescence immunoassay
• B. Enzyme-multiplied immunoassay technique
• C. Fluorescent polarization immunoassay
• D. High-performance liquid chromatography

Answer: (D)

The idea tested is that many immunoassays depend on a finite pool of binding sites on a macromolecule (usually an antibody). The signal you measure hinges on how much analyte competes for or occupies those limited binding sites, so the assay’s readout directly reflects the amount of analyte through this binding limitation. Chemiluminescence immunoassay, enzyme-multiplied immunoassay technique, and fluorescent polarization immunoassay all rely on antibodies with a limited number of binding sites to generate a detectable signal, either by competition or by changes in bound tracer. High-performance liquid chromatography, on the other hand, separates components of a mixture based on interactions with a stationary phase and a mobile phase, not on antibody binding. The detection is tied to the physicochemical properties of the analytes, not to a finite binding capacity of a macromolecule. So it does not rely on the limited-binding macromolecule principle.

The idea tested is that many immunoassays depend on a finite pool of binding sites on a macromolecule (usually an antibody). The signal you measure hinges on how much analyte competes for or occupies those limited binding sites, so the assay’s readout directly reflects the amount of analyte through this binding limitation. Chemiluminescence immunoassay, enzyme-multiplied immunoassay technique, and fluorescent polarization immunoassay all rely on antibodies with a limited number of binding sites to generate a detectable signal, either by competition or by changes in bound tracer.

High-performance liquid chromatography, on the other hand, separates components of a mixture based on interactions with a stationary phase and a mobile phase, not on antibody binding. The detection is tied to the physicochemical properties of the analytes, not to a finite binding capacity of a macromolecule. So it does not rely on the limited-binding macromolecule principle.