Abstract: Methods and compositions are provided for assays involving members of a specific binding pair ("sbp members") and members of a signal producing system ("sps members"). The signal producing system is capable of producing a detectible signal in relation to the presence or amount of an analyte in a sample suspected of containing the analyte. Exemplary of sps members are enzymes and enzyme substrates, which react with each other to produce a signal. The improvement of the present invention comprises temporarily delaying the production of the signal without subsequent reagent addition. The delay can be achieved by employing an inhibitor which can be an alternate substrate for the enzyme or a compound which reacts with the product of the enzyme and its substrate in an effective amount.

Abstract: Methods and compositions are provided for assays involving members of a specific binding pair ("sbp members") and members of a signal producing system ("sps members"). The signal producing system is capable of producing a detectible signal in relation to the presence or amount of an analyte in a sample suspected of containing the analyte. Exemplary of sps members are enzymes and enzyme substrates, which react with each other to produce a signal. The improvement of the present invention comprises temporarily delaying the production of the signal without subsequent reagent addition. The delay can be achieved by employing an inhibitor which can be an alternate substrate for the enzyme or a compound which reacts with the product of the enzyme and its substrate in an effective amount.