Bead-based analysis of a sample

Inventors

Fine, Alan Marc

Assignees

Alentic Microscience Inc

Abstract

Among other things, two or more different antibodies are caused to bind to one or more units of a chemical component in a sample. Each of the antibodies is attached to one or more beads (e.g., microbeads). The sample is situated on a surface of an image sensor. At the image sensor, light is received originating at a light source that is other than the beads. The received light includes light reflected by, refracted by, or transmitted through the beads. At least one image of the sample is processed to separately enumerate individual beads and complexes of two or more of the beads attached to the two or more antibodies that are bound to a unit of the chemical component. The results of the processing are used to identify a presence or a level of the chemical component in the sample.

Core Innovation

The described invention provides an imaging-based bead assay for chemical components in a sample disposed on a surface of an image sensor. Two or more antibodies bind a target unit of a chemical component, where a first antibody is attached to a bead and a second antibody is attached at a location on the surface of the image sensor or on a second surface. Light originating at a light source and reflected by, refracted by, or transmitted through the bead is received at the image sensor, and one or more images of the sample including the bead attached to the first antibody are captured.

The method identifies the bead in the at least one image and identifies, in the same images, the location at which the second antibody is attached on the surface of the image sensor or on the second surface based on the identification of the bead. The presence or level of the chemical component in the sample is then determined based on a correspondence between the second antibody attached at the identified location and the chemical component. The approach includes enumerating singleton beads and bead complexes (doublets/triplets) to infer the presence or concentration of the target.

The disclosure further describes multiplexing options using bead characteristics such as color, size, shape, birefringence, or texture, and includes formats that use fixed capture-antibody arrays with bead-coupled detection antibodies positioned relative to an image sensor surface. Additional disclosed use cases include analysis in a monolayer configuration on a surface with calibration via a standard curve for prolactin, and use in point-of-care contexts by combining with contact-CBC on the same image sensor.

Claims Coverage

The independent claim covers an imaging-based assay method using antibody-bead binding, bead-image identification, bead-linked localization of a second antibody on a sensor-facing surface or an opposing second surface, and determining presence or level of a chemical component by correlating the identified second-antibody location with the chemical component. The inventive features focus on where the second antibody is attached, imaging of light reflected, refracted, or transmitted by the bead, identifying the bead and the second-antibody attachment location based on bead identification, and determining presence or level from the correspondence.

Across the independent claim and its refinements, the coverage centers on an imaging workflow where a bead attached to a first antibody is imaged via reflected, refracted, or transmitted light, the bead is identified, and that identification is used to localize where the second antibody is attached on the sensor or an opposing surface. Presence or level of the chemical component is then determined through correspondence between the localized second antibody and the chemical component, with disclosed refinements for second-surface or sensor attachment geometry, monolayer configuration, array-based multiplexing, and a blood-plasma-only optical condition.

Stated Advantages

Documented Applications