Abstract: The invention relates to an in vitro diagnostic method for quantification of a clinical chemistry analyte from a clinical sample wherein the clinical chemistry analyte undergoes a chemical reaction or reactions with a reagent or reagents in one or several steps, or in a reaction sequence, or catalyzes a chemical reaction, or reactions, or a reaction in a reaction sequence of a reagent or reagents, in one or several steps, in a reaction system. The reaction or reactions or reaction sequence result in a change of a measurable property of a compound or compounds of said reaction or reactions or reaction sequence.

Abstract: The invention relates to an in vitro diagnostic method for quantification of a clinical chemistry analyte from a clinical sample wherein the clinical chemistry analyte undergoes a chemical reaction or reactions with a reagent or reagents in one or several steps, or in a reaction sequence, or catalyses a chemical reaction, or reactions, or a reaction in a reaction sequence of a reagent or reagents, in one or several steps, in a reaction system. The reaction or reactions or reaction sequence result in a change of a measurable property of a compound or compounds of said reaction or reactions or reaction sequence.

Abstract: A method for measuring the end point and for monitoring the real time kinetics of a bioaffinity reaction in biological fluids and suspensions, employing microparticles as bioaffinity binding solid phase, biospecific reagent labelled with a fluorescent label and a fluorescence detection system which is based on two-photon fluorescence excitation, contacting the analyte, the labelled reagent and the solid phase simultaneously, focusing a two-photon exciting laser beam into the reaction suspension and measuring the fluorescence signal emitted by the microparticles from one particle at a time when they randomly float through the focal volume of the laser beam. In this method the signal is monitored kinetically to obtain information about the analyte concentration before the reaction approaches the highest point of the response. Since the growth rate of the signal intensity is directly proportional to the analyte concentration, the analyte concentration can be predicted in the initial phase of the reaction.

Abstract: A homogeneous biospecific assay method for an analyte in solution or in a biological suspension, in which a biospecific reagent competitively binding an analyte and a ligand labeled with a fluorescent molecule, is reacted with and bound to a solid phase, and in which the free labeled ligand is extracted is excited with two-photon excitation by focusing a laser beam suitable for two-photon excitation into the sample volume; and the concentration of the analyte is calculated based on the photon emission contributed by the free labeled ligand.

Abstract: A method for quantitatively measuring nucleic acid amplification reactions, especially the polymerase chain reaction, employing microparticles as hybridization solid phase, a probe sequence labeled with a fluorescent label and a fluorescence detection system which is based on two-photon fluorescence excitation, contacting all the amplification reaction components and the solid phase simultaneously in a closed cuvette, performing the amplification reactions in the same cuvette, focusing a two-photon exciting laser beam into the cuvette during the amplification cycles and measuring the fluorescence signal emitted by the microparticles from one particle at a time when they randomly float through the focal volume of the laser beam. The features of this invention allow a method and device for performing a fast quantitative nucleic acid amplification assay of single or multiple target sequences in a very small closed sample volume.

Abstract: This invention is thus related to a biospecific multiparameter assay employing single molecule detection. In particular, this invention is related to a new method for determination of several different biomolecules simultaneously in the same reaction solution. The method uses a fluorescent label for labelling biospecific primary probes and a combination of other labels, bound to secondary probes. Complexes are formed comprising primary probes, analyte molecules and secondary probes in the biospecific reaction. These single molecule complexes are counted selectively while discriminating the signals from other fluorescent molecules using confocal fluorometry or two-photon excitation fluorometry including an auto- and cross-correlator for the signals obtained from said fluorescent labels.

Abstract: This invention is related to a flow fluorometric device and method employing a two-photon excitation and/or confocal optical set-up. The optical set-up of this invention is optimal for counting small fluorescent biological particles. The active focal volume is diffraction-limited and consequently much smaller than the volume of the flow channel. The excitation and detection concept has been found very efficient for rejection of the background signal. An objective lens with large numerical aperture for focusing the laser and for collecting the fluorescence is used and this restricts the active volume of measurement to a diffraction-limited volume which approximately corresponds to a volume of femtoliter. This volume is significantly smaller than the detection volume of ordinary flow cytometry.

Abstract: The object of this invention is an improved method for biospecific multiparameter assay method based on the use of different categories of microparticles as solid support for different bioaffinity reagents. This invention allows the use of microparticles of small size and with very moderate monodispersity and conventional short decay time fluorescent labels for labelling the biospecific reactants. The high sensitivity of this method is based on the use of confocal excitation and detection, or alternatively, two-photon excitation for measurement of the biospecific reaction. The identification of the category of the microparticle is based on the use of fluorescent or Raman scattering indicators associated with the microparticles representing different analytes.

Abstract: A method for the two-photon excitation of long-lived fluorescent or phosphorescent dyes with long low-power pulses. In the method time-resolved detection is used to detect long-lived dyes. In the method long-lived dyes are excited to the excited state with light pulses of long duration via double-photon absorption. In the two-photon absorption process the chromophor of the dye molecule is excited through the summation of the energies of two or more photons when they are simultaneously absorbed. As the method is based on the use of pulses of long duration and on time-resolved detection the peak power of the pulses may be kept low. Long pulses of low power can be produced with a great variety of low-power light sources. The light source may in this case be e.g. a semiconductor laser. The excitation technique according to the invention may exploit the doubling or multiplication of the excitation wavelength or the nonlinearity of the two-photon absorption process.

Abstract: Method for quantitative determination of a biospecific affinity reaction in which an immunochemical compound labelled with a lanthanide chelate is used which can be detected by means of time-resolved fluorescence in which the amount of labelled compound present in the biospecific affinity reaction can be measured without the separation of free and biospecifically bound labelled compound having to be carried out.

Abstract: An improved method of determining the nature of a substance by fluoroscence spectroscopy wherein a fluorescent marker is coupled to the molecules of the substance comprises the use of a marker having a longer period of fluorescence than those of possible sources of noise and by employing an exciting radiation pulse of short duration so that the fluorescence of the marker is detected after the objectionable sources of fluorescence have ceased; the marker including a fluorescent lanthanide chelate complex.

Abstract: In an instrument for measuring radioactivity, the total measuring time for each sample is optimized by considering the maximum acceptable total counting error as well as the count rate. Each sample is counted for a period of time that is considerably shorter than the required measuring time but long enough to estimate the average pulse frequency, then the measuring time is determined as a function of the estimated pulse frequency and of the experimental error as determined by the channels ratio method.