Process and test carrier for the determination of an analyte

Abstract

The present invention provides a process for the determination of an analyte in a body fluid, in which there are used two binding components capable of specifically binding with one another, one of the binding components being enzyme-labelled and not carrier-fixed and the other binding component being carrier-fixed. The process contains a step in which the binding components are incubated with one another so that binding reaction takes place. The amount of enzyme-labelled binding component not bound to the carrier-fixed binding component is a measure of the concentration of the analyte which is determined by allowing the labelling enzyme to act upon a substrate producing a detection signal. During the specific binding reaction, incubation is carried out simultaneously with a non-fixed substrate of the labelling enzyume which does not produce a detection signal and with a carrier-fixed substrate of the labelling enzyme which produces a detection signal, the substrate not producing a detection signal being so chosen with regard to the amount used and affinity to the labelling enzyme in relation to the amount of the substrate producing a detection signal and its affinity to the labelling enzyme and in relation to the total activity of the labelling enzyme that the enzyme-catalyzed reaction of the substrate producing a detection signal is delayed until the specific binding reaction between the binding components has substantially taken place.