Method and apparatus for making measurements of patterns of magnetic particles in lateral flow membranes and microfluidic systems

• US 6,597,176 B2
• Filed: 07/23/2001
• Issued: 07/22/2003
• Est. Priority Date: 11/21/1997
• Status: Expired due to Term

• Current Assignee: Quantum Design International, Inc.
• Original Assignee: Quantum Design, Inc.
• Inventors: Diederichs, Jost Hermann, Jensen, Kurt Gordon, Black, Randall Christopher, Simmonds, Michael Bancroft
• Primary Examiner(s): PATIDAR, JAY M
• Application Number:
  US09/911,934
• Publication Number:
  US 20010052769A1
• Time in Patent Office: 729 Days
• Field of Search: 324/239, 324/204, 324/71.4, 324/226, 324/233, 324/234, 324/236, 324/214, 324/215, 422/68.1, 422/48, 436/526
• US Class Current: 324/326
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01N 27/745 for detecting magnetic beads used in biochemical assays concerning the assays G01N33/54326; sensors therefor G01R33/1269; automatic analysers therefor G01N35/0098
• CPC Class Codes: G01N 35/0098 involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: G01R 33/12 Measuring magnetic properties of articles or specimens of solids or fluids involving magnetic resonance G01R33/20
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/838 Magnetic property of nanomaterial
• CPC Class Codes: Y10S 977/96 Of magnetic property

Abstract

An apparatus is provided for quantitatively determining amounts and identities of substances whithin patterns of magnetic particles, such as within lateral flow membranes, microfludic systems, and the like. Magnetic particles are complexed with substances to be determined and are excited in an oscillating magnetic field. The magnetizations of the magnetic particles are thereby caused to oscillate at the excitation frequency to create their own fields. These fields are inductively coupled to at least one sensor such as sensing coils fabricated in a gradiometer configuration. The output signals from the sensing coils are appropriately amplified and processed to provide useful output indications.

Claims

1. An apparatus for quantitative measurement of analyte particles using magnetically susceptible particles, comprising:

a sample holder including;

an inlet for introduction of analyte particles;

a lateral flow membrane through which the analyte particles may flow, the lateral flow membrane including a predefined area containing a plurality of bound magnetically susceptible particles, whereby flowing analyte particles may become bound to the bound magnetically susceptible particles;

a magnetic field source to apply an alternating magnetic field to the samples in the predefined area;

a magnetic field sensor having output signal conductors to communicate output signals; and

an electronic signal processor to convert the output signals from the sensor to provide a signal indicative of the quantity of the samples in the predefined area.

2. An apparatus for quantitative measurement of analyte particles using magnetically susceptible particles, comprising:

a microfluidic sample holder including;

an inlet channel for introduction of sample particles including analyte particles; and

a sample analysis chamber connected to the inlet channel;

a magnetic field source to apply an alternating magnetic field to the samples in the sample analysis chamber;

a magnetic field sensor having output signal conductors to communicate output signals; and

an electronic signal processor to convert the output signals from the sensor to provide a signal indicative of the quantity of the samples in the sample analysis chamber.

3. The apparatus of claim 2, wherein the analyte particles are combined with the magnetically susceptible particles.

4. The apparatus of claim 2, further comprising:

at least one reagent chamber containing a solution of magnetically susceptible particles; and

at least one mixing chamber connected to the reagent chamber and to the inlet channel.

5. The apparatus of claim 2, further comprising a measurement chamber connected to the sample analysis chamber via a channel.

6. The apparatus of claim 5, further comprising an outlet channel connected to one of the sample analysis chamber or the measurement chamber.