Other

Arctic Diagnostics Oy

Arcdia International Oy Ltd

Erkki Soini

Pekka H&auml;nninen

Juhani Soini

Pekka Hanninen

Niko Meltola

Aloksi Soini

Aleksi Soini

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. Characteristic for the method is that said chemical reaction or reactions or reaction sequence results in formation of a two-photon fluorescent compound, or a change in two-photon fluorescence properties of the reaction system comprising at least one two-photon fluorescent compound, and the analyte is quantified by exciting said two-photon fluorescent compound or compounds and measuring two-photon exited fluorescence, and relating said measured fluorescence to method standardization data based on measurements obtained from reference material of said analyte. The present invention also relates to use of a fluorometric device employing two-photon fluorescence excitation for quantification of a clinical chemistry analytes. The present invention further relates to a system for quantification of clinical chemistry analytes from samples containing the analyte. Characteristic for the system is that it comprises a fluorometric device employing two-photon excited fluorescence for quantifying one or several clinical chemistry analytes, and a data processing unit with software for dedicated data reduction for quantification of the analyte or analytes using said fluorometric device. The present invention further relates to a software product for the system.

Use of two-photon excited fluorescence in assays of clinical chemistry analytes

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. The growth rate monitoring also predicts whether the analyte concentration is higher than the binding capacity of the reagent and whether the reaction will be continued over the highest point of the response curve.

Biospecific, two photon excitation, fluorescence detection and device

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.

Homogeneous biospecific assay using a solid phase, two-photon excitation and confocal fluorescence detection

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.

Method and a device for monitoring nucleic acid amplification reactions

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.

Biospecific assay method

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.

Flow fluorometric method

Biospecific multiparameter assay method

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. The method may be used for the detection of the fluorescence or phosphorescence from long-lived dyes for the determination of biospecific binding in applications of analytical or microscopic methods.

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Kirjala, Finland

Erkki Soini