Detection of clusters of magnetic particles

Patent metadata

Field	Value
Publication number	US-10036729-B2
Application number	US-201214125618-A
Country	US
Kind code	B2
Filing date	Jun 18, 2012
Priority date	Jun 30, 2011
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

The invention relates to a method and a sensor device ( 100 ) for the detection of clusters (C) of magnetic particles (MP) in a sample volume ( 111 ), particularly of clusters (C) consisting of two magnetic particles (MP) with different binding sites that are bound to a target molecule in a sandwich configuration. Output light (L 2 ) originating from an interaction of input light (L 1 ) with clusters (C) of magnetic particles (MP) is detected. Moreover, the magnetic particles (MP, C) are actuated by a magnetic actuation field (B), wherein said actuation is at least once interrupted by a pause. In this way a high output signal can be achieved that properly reflects the amount of specifically bound clusters (C).

First claim

The invention claimed is:

1. A method for detection of clusters (C) of magnetic particles (MP) bound to target molecules, respectively, in a sample volume, the method comprising:
irradiating the sample volume with input light (L 1 );
actuating the magnetic particles in the sample volume by exposing the sample volume to a rotating magnetic actuation field (B) to form said clusters rotating in the magnetic actuation field, such that the sample volume comprises bound magnetic particles and unbound magnetic particles, wherein said magnetic actuation field is interrupted by at least one pause; and
detecting output light (L 2 ) during the actuation of the magnetic particles, the output light originating from an interaction of the input light (L 1 ) with the clusters (C) of magnetic particles (MP) in the sample volume, wherein intensity of said output light is modulated by the rotation of said clusters in said rotating magnetic actuation field;
wherein a duration of the at least one pause ranges between about 0.1 s and about 10 s.

2. The method according to claim 1 , wherein the duration of the at least one pause and/or a number of pauses is experimentally determined.

3. The method according to claim 1 , wherein the duration of the at least one pause ranges between about 1 s and about 2 s.

4. The method according to claim 1 , wherein the magnetic actuation field (B) is interrupted by about 10 to about 50 pauses.

5. The method according to claim 1 , wherein each of the detected clusters (C) is formed by two magnetic particles (MP) bound to one of the target molecules.

6. The method according to claim 1 , wherein the sample volume comprises magnetic particles (MP) of two kinds able to bind to a target molecule in the sample volume in a sandwich configuration.

7. The method according to claim 1 , wherein the output light (L 2 ) comprises input light (L 1 ) which was scattered by the clusters (C) of magnetic particles in the sample volume.

8. The method according to claim 1 , further comprising:
detecting an amount of clusters in the sample volume based on the modulated intensity of the output light.

9. The method according to claim 8 , further comprising:
determining an amount of the target molecules in the sample volume based on the detected amount of clusters.

10. A method of determining an amount of target molecules in a sample, the method comprising:
providing magnetic particles coated with antibodies in the sample;
exposing the sample to a magnetic field, causing formation of clusters comprising at least two magnetic particles bound to a target molecule via the antibodies;
rotating the magnetic field, causing rotation of the clusters in the sample, wherein said magnetic field is interrupted by at least one pause;
irradiating the sample with input light;
detecting output light during rotation of the magnetic field, the output light originating from an interaction of the input light with the clusters, wherein intensity of the output light is modulated by the rotation of the clusters in the rotating magnetic field; and
determining an amount of the target molecules in the sample based on an amount of clusters detected using the modulated intensity of the output light.

11. The method of claim 10 , wherein the at least two magnetic particles bound to each of the target molecules form a sandwich configuration, comprising two magnetic particles of different kinds coupled by the target molecule.

12. The method of claim 10 , wherein a duration of the at least one pause ranges between about 0.1 s and about 10 s.

Assignees

• Ranzoni Andrea
• Prins Menno Willem Jose
• Koninklijke Philips Nv

Inventors

• Ranzoni Andrea
• Prins Menno Willem Jose

Classifications

• G01N27/745 Primary

  for detecting magnetic beads used in biochemical assays (concerning the assays G01N33/54326; sensors therefor G01R33/1269; automatic analysers therefor G01N35/0098) · CPC title

• G01N2446/00

  Magnetic particle immunoreagent carriers · CPC title

• G01N2021/1727

  Magnetomodulation · CPC title

• G01N21/51

  inside a container, e.g. in an ampoule (G01N21/53 takes precedence) · CPC title

• G01N21/1717

  with a modulation of one or more physical properties of the sample during the optical investigation, e.g. electro-reflectance · CPC title