Abstract: Polynucleotide sequences in a sample of biological or nonbiological material are detected by a method involving fixing of the sequences on a solid support and forming an entity between the fixed sequences and chemically-labeled polynucleotide or oligonucleotide probes having a sequence complementary to the fixed sequence for determining the identification and/or presence of the target polynucleotide sequences. The chemical label covalently or noncovalently attached to the probe comprises a signalling moiety capable of generating a soluble signal detectable by spectrophotometric assay techniques.

Abstract: A method is disclosed to detect the presence of an analyte. The method involves forming a complex comprising the analyte and a binding entity. The binding entity comprises a first partner of an energy transfer system. The complex is then contacted with a reporting entity to form a unit. The reporting entity comprises a second partner of the energy transfer system. The first partner and the second partner are within Furster's radius of each other in the formed unit. The unit is irradiated with energy which can only be absorbed by one of said partners, namely, the energy donor, which then emits fluorescent energy. Some of this energy is absorbed by the other of said partners, namely, the energy acceptor, which also emits fluorescent energy. However, the fluorescent energy of the energy acceptor is of longer wavelength and in addition may be of substantially greater duration than the fluorescent energy of the energy donor.