Abstract: An attenuator is included in a reagent medium of a luminescent specific-binding assay to suppress undesirable extraneous light. In one such assay, an analyte in a sample is reacted with a specific binding partner attached to a solid surface, forming an immobilized pair at the surface. One member of the immobilized pair is then allowed to react with a specific binding partner previously conjugated with one component of a luminescent reaction system, and the remaining components are provided in the reagent medium. The resulting light emitted in the luminescent reaction is recorded on photographic film or other photodetector as a measure of the presence and quantity of the analyte in the sample.

Abstract: Method and apparatus for use in accurately measuring the binding reactions occurring between a predetermined class of components in a liquid specimen and their corresponding binding conjugates coated on separate test regions of a carrier. The carrier further includes a reference region that is uncoated, and the carrier is adapted for simultaneous contact of all of its regions with the liquid specimen. Any resulting binding reaction on each test region indicates both specific binding to the coated component as well as non-specific binding, and any resulting binding reaction on the reference region indicates merely non-specific binding. The measurements for the test regions are all reduced by an amount determined in accordance with the measurement for the reference region, to reduce the effects of non-specific binding on those measurements and thereby provide accurate measurements of the specific binding on each coated component.