Methods and apparatus for magnetic multi-bead assays
Inventors
Connolly, Colin B. • Randall, Jeffrey D. • Pena, John C.
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11513115-B2
Publication Date
2022-11-29
Expiration Date
Abstract
The present application discloses methods and apparatus for detecting a complex including an analyte that include contacting a sample in a solution with a population of functionalized beads of a first type, which are magnetic functionalized beads and are functionalized to include a first moiety that associates with an analyte under suitable conditions, contacting the sample solution with a population of functionalized beads of a second type, which are functionalized to include a second moiety that associates with the analyte under suitable conditions, contact resulting in formation of a complex including one of the first type of functionalized bead, the analyte, and one of the second type of functionalized bead, and detecting the complex including the analyte by detecting magnetic fields produced by the magnetic functionalized bead and by detecting the functionalized bead of the second type associated with the analyte in the complex.
Core Innovation
The invention provides a bead-based magnetic assay system for detecting a complex including an analyte. The complex includes one of a first type of functionalized beads and one of a second type of functionalized beads that associate with the analyte under suitable conditions, and the first and second functionalized bead types are both magnetic functionalized beads with a magnetic property distinguishable between the bead types.
The system uses a diamond substrate including a plurality of nitrogen-vacancy ODMR centers formed in an upper surface of the diamond substrate. Incident light excites electrons within the ODMR centers from a ground state to an excited state, and the ODMR centers produce emitted light when illuminated by the incident light, with a microwave field having frequencies corresponding to ground state transitions influencing characteristics of the emitted light from the magnetic functionalized bead associated with the analyte in the complex.
The emitted light is imaged by an optical imaging system into spatially resolved images of the magnetic functionalized beads of the first and second type. A bias magnetic field is applied by a first magnet on the complex disposed over the ODMR centers, and a second magnet applies a magnetizing magnetic field greater than the bias magnetic field on the complex prior to imaging the emitted light.
Claims Coverage
Independent claim clm-00001 defines an ODMR-based magnetic multi-bead assay system with imaging-based discrimination between two distinguishable magnetic bead types, including bias and magnetizing magnetic fields. The independent claim is supported by dependent claims that add bead material and structure constraints, bead size constraints, and allowable moiety types for analyte association.
Optically detected magnetic resonance bead assay with two distinguishable magnetic bead types
A bead-based magnetic assay system for detecting a complex including an analyte, using a plurality of functionalized magnetic beads of a first type and a plurality of functionalized magnetic beads of a second type, where the second type has a magnetic property distinguishable from the first type and both bead types include moieties that associate with the analyte under suitable conditions.
Diamond nitrogen-vacancy ODMR optical imaging of bead-associated magnetic fields
A diamond substrate including nitrogen-vacancy ODMR centers in an upper surface, together with a light source to excite electrons in the ODMR centers, a microwave source to generate a microwave field with frequencies corresponding to ground state transitions, and an optical imaging system having an imaging sensor that images emitted light into spatially resolved images of magnetic functionalized beads of the first and second type.
Bias and stronger magnetizing fields prior to imaging
A first magnet applies a bias magnetic field on the complex disposed over the ODMR centers, and a second magnet applies a magnetizing magnetic field greater than the bias magnetic field on the complex prior to imaging the emitted light.
Magnetizing field magnitude constraint
The system applies a magnetizing magnetic field greater than a numerical threshold on the complex prior to imaging the emitted light.
Nonmagnetic encapsulation of ferromagnetic material for the second bead type
Functionalized beads of the second type include a nonmagnetic layer that encapsulates ferromagnetic material.
Superparamagnetic iron oxide for the first bead type
The superparamagnetic functionalized beads include iron oxide particles.
Bead diameter range constraint for both bead types
Each of the first and second functionalized beads has a diameter within a defined range.
Moiety types for analyte association
Each of the first and second moieties that associates with the analyte is selected from receptor, protein, antibody, cell, virus, or nucleic acid sequence.
Across the claim set provided, the inventive core is an ODMR-based magnetic assay that detects an analyte complex formed with two distinguishable magnetic bead types and reconstructs bead co-presence using optical imaging of ODMR-emitted light influenced by microwave excitation under bias and stronger magnetizing magnetic fields. Dependent claims further specify material and structure, constrain bead size, and enumerate moiety types used for analyte association.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?