Diagnostic assay using magnetic particles
AssigneeOsler Diagnostics Limited
InventorsKonstantinos PSARROS, Peter READER, Fatiha TAYLOR, Laure CARRIQUE, Vincent LINDEN, Barbara SIMOES, Theo VOGIAT-ZOGLOU, Maryam Noor ALI
Life of this patent
Estimating the term…
Abstract
The present invention relates to an apparatus and method for determination of analytes in biological samples by immunoassays incorporating magnetic capture of beads on a sensor, capable of being used in the point-of-care diagnostic field.
Claims25
1) A method for measuring an analyte of interest in a biological sample comprising:
- combining said biological sample with a composition comprising:
- magnetically susceptible beads conjugated to a first antibody or antigen binding portion thereof capable of binding said analyte of interest;
- and
- a second antibody or antigen binding portion thereof capable of binding said analyte of interest conjugated to an enzyme;
- retaining the magnetically susceptible beads on an electrode using a magnetic field;
- contacting the magnetically susceptible beads with a substrate for the enzyme, wherein the enzyme substrate is converted by the enzyme into an electroactive molecule;
- and
- obtaining an electrochemical measurement using said electrode.
4) The method for measuring an analyte of interest in a biological sample according to any preceding claim, further comprising:
- incubating the combined biological sample and composition such that the first and/or second antibodies bind the analyte of interest.
5) The method for measuring an analyte of interest in a biological sample according to any preceding claim, further comprising:
- retaining the magnetically susceptible beads in a fixed position using a magnetic field;
- and
- washing the magnetically susceptible beads.
8) The method for measuring an analyte of interest in a biological sample according to any preceding claim, wherein the magnetic field is generated by:
- a. a fixed magnet;
- or
- b. an electromagnet.
10) The method for measuring an analyte of interest in a biological sample according to any preceding claim, wherein the magnetic field is located within a microfluidic device having a flow conduit and wherein the magnetic field is modulated by actuating the magnet in a direction perpendicular to the direction of flow within said flow conduit.
15) The method for measuring an analyte of interest in a biological sample according to any preceding claim wherein the electrode is a carbon ink electrode.
16) The method for measuring an analyte of interest in a biological sample according to any preceding claim wherein the analyte of interest is brain natriuretic peptide or N-terminal pro-BNP.
18) The method for measuring an analyte of interest in a biological sample according to any preceding claim wherein the enzyme is horseradish peroxidase (HRP) or alkaline phosphatase (ALP).
19) The method for measuring an analyte of interest in a biological sample according to any preceding claim wherein the substrate for the enzyme is selected from the list consisting of:
- 3,3′,5,5′-Tetramethylbenzidine (TMB), 2,2′-Azinobis [3-ethylbenzothiazoline-6-sulfonic acid]-diammonium salt (ABTS), o-phenylenediamine dihydrochloride (OPD), para-nitrophenyl phosphate (PNPP) and BCIP/NBT (a combination of BCIP (5-Bromo-4-chloro-3-indolyl phosphate) and NBT (nitro blue tetrazolium)).
20) The method for measuring an analyte of interest in a biological sample according to any preceding claim wherein the electrochemical measurement is an amperometric, voltametric, potentiometric, impedimetric, or electrochemical impedance spectroscopic measurement, preferably a chronoamperometric measurement.
21) The method according to any preceding claim, wherein the method of measuring is a sandwich immunoassay.
22) The method according to any preceding claim, wherein the at least 50% (for example, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% of the beads) measured by % weight are retained at the surface of the electrode.
Dependencies are inferred from the claim text.