Abstract: This invention relates to a bioassay method for detecting and/or quantitating a short single-stranded nucleic acid analyte employing a binary probe system, where at least one of the two discrete oligonucleotide probe parts of the binary probe has partially double-stranded (self-complementary) stem-loop structure at one terminus and single-stranded overhang sequence region at the other terminus, where the single-stranded terminal regions of both discrete parts of the binary probe hybridize to adjacent complementary regions in the sequence of the nucleic acid analyte molecule, and at least one discrete part of the binary probe comprising a stem-loop structure and single-stranded overhang sequence region hybridizes to terminal region in the sequence of the nucleic acid analyte molecule forming a nick structure.

Abstract: A bioassay employing a first group including a lanthanide ion carrier chelate and a first recognition element, a second group including an antenna ligand and a second recognition element; where the lanthanide ion carrier chelate binds strongly to lanthanide, or the lanthanide ion carrier chelate binds moderately to lanthanide, and an agent complexing the lanthanide ion is additionally employed at a concentration of at least 1 pmol/l. The antenna ligand binds weakly to the lanthanide ion. Analyte recognition by the first recognition element and by the second recognition element results in either chelate complementation and increased fluorescence, or chelate discomplementation and decreased fluorescence.

Abstract: The invention relates to analysis of photon upconversion luminescent inorganic lanthanide-doped nanomaterials and/or separation and/or purification of them from other materials such as biomolecules and/or chemicals used e.g. for bioconjugation in preparation of reagents based on upconverting lanthanide nanoparticles for bioanalytical assays. The invention utilizes a high gradient magnetic separator (HGMS) and it can be applied from large submicron materials to small nanoparticles just nanometers or tens of nanometers in diameter. It is also scalable from small analytical scale to preparative scale.

Abstract: Method for detecting nucleic acids which employs a double-stranded oligonucleotide probe containing i) a first probe including a first label moiety, and ii) a second probe partially complementary with the first probe and including a second label moiety capable of interacting with the first moiety when brought in close proximity with each other, the second moiety being a quencher or acceptor of emission of the first moiety. The first or second probe includes a sequence complementary to that of a target nucleotide, and the second or first probe, respectively, includes a sequence complementary to a complement of the target nucleotide sequence of the nucleic acid to be detected. Oligonucleotides for determining Chlamydia trachomatis are also disclosed.

Abstract: A homogenous bioassay including i) a first group containing a short lifetime fluorescent acceptor, and ii) a second group containing a quencher, with the first and second groups linked by at least a first linkage. The bioassay measures the acceptor's fluorescence increase resulting from cleavage of the first linkage and also includes iii) a third group containing a donor for energy transfer to the acceptor, where the donor is an up-conversion fluorescent compound, a long-lifetime fluorescent compound or an electrogenerated luminescent compound. A conformational or terminal epitope is created on the first group through linkage cleavage, and the third group includes a binder with affinity for this epitope. The acceptor's fluorescence is caused by exciting the donor. Also disclosed are bioassay kits for this method.

Abstract: Method for detecting nucleic acids which employs a double-stranded oligonucleotide probe containing i) a first probe including a first label moiety, and ii) a second probe partially complementary with the first probe and including a second label moiety capable of interacting with the first moiety when brought in close proximity with each other, the second moiety being a quencher or acceptor of emission of the first moiety. The first or second probe includes a sequence complementary to that of a target nucleotide, and the second or first probe, respectively, includes a sequence complementary to a complement of the target nucleotide sequence of the nucleic acid to be detected. Oligonucleotides for determining Chlamydia trachomatis are also disclosed.

Abstract: A bioassay employing a first group including a lanthanide ion carrier chelate and a first recognition element, a second group including an antenna ligand and a second recognition element; where the lanthanide ion carrier chelate binds strongly to lanthanide, or the lanthanide ion carrier chelate binds moderately to lanthanide, and an agent complexing the lanthanide ion is additionally employed at a concentration of at least 1 pmol/l. The antenna ligand binds weakly to the lanthanide ion. Analyte recognition by the first recognition element and by the second recognition element results in either chelate complementation and increased fluorescence, or chelate discomplementation and decreased fluorescence.

Abstract: Thus this invention relates to a nanoparticle, useful for bioaffinity assays. The nanoparticle has a self-assembling shell built up of several protein and/or peptide subunits, which protein and/or peptide subunits can be of one or several different types, assembled in an organized manner to form the shell having an inner surface facing the inside and an outer surface facing the outside of said particle. One or several of the types of subunits have one or several first binding moieties per type of subunit with the binding moiety facing the outside of the particle for binding of any specific ligand binding protein; and the particle contains within its shell a marker and/or one or several of the types of subunits have one or several second binding moieties per type of subunit with the binding moiety facing the inside and/or the outside of the particle for binding a marker; and the marker or markers enables detection of the particle.

Abstract: A method to correct measurement error in a resonance energy-transfer assay, including exciting anti-Stokes photoluminescent donors with at least one wavelength of light which is greater than an emission wavelength of acceptor molecules; measuring emission at the acceptor's emission wavelength and which differs from the donor's emission wavelength in at least two different time windows; a first time window within the time window defined by the excitation light pulse and a second non-overlapping time window which follows the first time window; and correcting the emission signal, which includes signals originating from non-radiative and radiative energy transfer, within the first time window by estimating the ratio of the signals from non-radiative and radiative energy transfer or the signal originating from radiative energy transfer using at least one emission signal measured in the second time window.

Abstract: A homogenous bioassay including a first group including an acceptor which is a short lifetime fluorescent compound capable of energy transfer, and a second group including a quencher which is capable of energy transfer from an acceptor. The increase or decrease of the acceptor's fluorescence resulting from lengthening or shortening of the distance between the acceptor and quencher is measured. The bioassay also includes a third group including a donor for energy transfer to the acceptor, which donor is an up-conversion fluorescent compound, a long-lifetime fluorescent compound or an electrogenerated luminescent compound. The first group includes a tag, the third group includes a binder having a high affinity for binding to the tag. Fluorescence of the acceptor is brought about by exciting the donor resulting in energy being transferred from the donor to the acceptor.

Abstract: A homogenous bioassay including i) a first group containing a short lifetime fluorescent acceptor capable of energy transfer, and ii) a second group containing a quencher capable of energy transfer from an acceptor, with the first and second groups linked by at least a first linkage. The bioassay measures the acceptor's fluorescence increase resulting from cleavage of the first linkage. The bioassay also includes iii) a third group containing a donor for energy transfer to the acceptor, where the donor is an up-conversion fluorescent compound, a long-lifetime fluorescent compound or an electrogenerated luminescent compound. A conformational or terminal epitope is created on the first group through cleavage of the linkage, and the third group includes a binder with affinity for this conformational or terminal epitope. The acceptor's fluorescence is brought about by exciting the donor. Also disclosed are kits for homogenous bioassays according to the method of the invention.

Abstract: A homogeneous bioassay including a first group labelled with an energy donor and a second group labelled with an energy acceptor, where the donor is a luminescent lanthanide label capable of up-converting a lower-energy excitation to a higher-energy emission, where the acceptor is either a luminescent or a non-luminescent label, and where the increase or decrease, respectively, in energy transfer from the donor to the acceptor resulting from shortening or lengthening of the distance between the labels is measured. The assay is performed in a biological fluid which absorbs radiation in the wavelength range 300 to 600 nm, the measurement is carried out at a wavelength >570 nm, and the donor label, which is excitable at wavelength longer than its emission wavelength, is excited in the wavelength window in which the biological fluid does not essentially absorb the excitation radiation.

Abstract: This invention relates to a homogenous bioassay for use in measurement of biological activity, its modulation or analyte concentration of a sample, said bioassay comprising a first group comprising an acceptor, which acceptor is a short lifetime fluorescent compound capable of energy transfer, and a second group comprising a quencher, which quencher is capable of energy transfer from an acceptor. The increase or decrease, respectively, of fluorescence of said acceptor due to the decrease or increase, respectively, of energy transfer from said acceptor to said quencher resulting from lengthening or shortening, respectively, of the distance between said acceptor and quencher is measured.

Abstract: This invention relates to a method comprising the steps of a) contacting a sample containing a sample substance and a solid phase comprising a signal element, and optionally a substance containing a signal element, i.e. a signal element substance; wherein at least one of said sample substance, said solid phase, and said signal element substance comprises a signal element; wherein the surface of the solid phase contains no specific binding partners; and wherein the solid phase is capable of binding said sample substance nonspecifically, preferably through adsorption, to said solid phase, and b) detecting a signal change resulted from binding of said sample substance and/or signal element substance to said solid phase, and/or change in distance from said sample substance and/or said signal element substance to said solid phase.

Abstract: This invention relates to a method to correct for error in an anti-Stokes photoluminescence measurement in a Foerster-type resonance energy-transfer assay. The method comprises the steps of exciting anti-Stokes photoluminescent molecules, ions, phosphors, chelates, or particles, i.e. donors of the assay, with one wavelength or multiple wavelengths of light wherein the wavelength or wavelengths are greater than that of an emission wavelength of acceptor molecules in the assay; measuring emission light signal at a wavelength, which is the emission wavelength of the acceptor molecules in the Foerster-type resonance energy-transfer assay, and which differs from the emission wavelength of the anti-Stokes photoluminescent donor in at least two different time windows; a first time window within the time window defined by the excitation light pulse, i.e.

Abstract: Thus this invention relates to a nanoparticle, useful for bioaffinity assays. The nanoparticle has a self-assembling shell built up of several protein and/or peptide subunits, which protein and/or peptide subunits can be of one or several different types, assembled in an organized manner to form the shell having an inner surface facing the inside and an outer surface facing the outside of said particle. One or several of the types of subunits have one or several first binding moieties per type of subunit with the binding moiety facing the outside of the particle for binding of any specific ligand binding protein; and the particle contains within its shell a marker and/or one or several of the types of subunits have one or several second binding moieties per type of subunit with the binding moiety facing the inside and/or the outside of the particle for binding a marker; and the marker or markers enables detection of the particle.

Abstract: This invention concerns a luminescence energy transfer based homogeneous bioassay comprising a first group labelled with an energy donor and a second group labelled with an energy acceptor, wherein the donor is a luminescent lanthanide label, said label being able to up-convert a lower-energy excitation to a higher-energy emission, the acceptor is either a luminescent or a non-luminescent label, and the increase or decrease, respectively, in energy transfer from the donor to the acceptor resulting from shortening or lengthening, respectively, of the distance between said labels is measured. According to the invention, the assay is performed in a biological fluid which absorbs radiation in the wavelength range 300 to 600 nm, the measurement is carried out at a wavelength>570 nm, and the donor label, which is excitable at wavelength longer than its emission wavelength, is excited in the wavelength window in which the biological fluid does not essentially absorb the excitation radiation.