Practice question

Analytical sensitivity depends on thermodynamic and structural variables governing immune complex formation. Antibody affinity constant dictates how tightly paratope holds epitope at low concentration. Epitope density and uniformity influence avidity, accessibility and number of binding sites per molecule. Matrix effects, incubation time and temperature further modulate kinetics. Chromogen purchase cost relates only to laboratory economics and procurement; it has no biochemical impact on molar detection limit, equilibrium binding or enzyme turnover rate. Therefore improving reagents quality rather than pricing considerations determines assay ability to distinguish low analyte levels from background.