Differential immunoassay
AssigneeSpectral Diagnostics, Inc.
InventorQinwei Shi
Life of this patent
Estimating the term…
Abstract
The invention provides assay methods and kits that in general measure the level of a first analyte in a sample reduced by the level of a second analyte present in the same sample. In one embodiment, where levels of a first analyte from a first source is desirably determined and first analyte in the sample released from a second source is accompanied by proportional co-release of a second analyte, the assay identifies the level of first analyte released only from the first source. For analytes within bodily fluids, the assay can differentiate between elevated levels of analyte specific to the particular physiological or pathological state and elevated levels not specific to the particular state, providing single tests with diagnostic utility.
Claims47
A method by which a sample is assayed to determine the presence or level therein of a first analyte relative to a second analyte, the method comprising the step of bringing the sample into contact with a labeling means adapted to label the first analyte through a binding interaction that is inhibited by the second analyte.
A method for identifying in a sample the presence or level of a preselected analyte originating from a target source, wherein any level of said preselected analyte in said sample originating from a source other than said target source is associated with a level in said sample of a marker from said source other than said target source, the method comprising conducting an assay following the sequential steps of
- (a) first contacting the sample with an analyte labeling reagent comprising
- (1) a mobile, labeled binding partner to one of the analyte or the marker,
- (2) a conjugate between the marker and one of biotin and streptavidin, and
- (3) binding partner to the preselected analyte conjugated to the other of biotin and streptavidin;
- and then
- (b) contacting the sample with an immobilized binding partner to the other of the preselected analyte and the marker;
- wherein the extent of labeling of the immobilized binding partner is indicative of the presence or level of the preselected analyte in the sample reduced by the level of the marker in the sample originating from the source other than the target source.
A method for identifying in a sample the presence or level of a preselected analyte originating from a target source, wherein any level of said preselected analyte in said sample originating from a source other than said target source is associated with a level in said sample of a marker from said source other than said target source, the method comprising conducting an assay following the sequential steps of
- (a) first contacting the sample with an analyte labeling reagent comprising
- (1) a mobile, labeled binding partner to the marker,
- (2) a conjugate between the marker and one of biotin and streptavidin, and
- (3) a binding partner to the preselected analyte conjugated to the other of biotin and streptavidin;
- and then
- (b) contacting the sample with an immobilized binding partner to the preselected analyte;
- wherein the extent of labeling of the immobilized binding partner is indicative of the presence or level of the preselected analyte in the sample reduced by the level of the marker in the sample originating from the source other than the target source.
A conjugate comprising an analyte or fragment thereof and streptavidin or a biotin-binding fragment or variant thereof, wherein independently, said analyte or fragment thereof in said conjugate is capable of being bound by an antibody to said analyte, and said streptavidin or biotin-binding fragment thereof in said conjugate is capable of binding to biotin.
A conjugate comprising an antibody to a first analyte or binding fragment thereof and a second analyte or fragment thereof, wherein independently, said antibody to said first analyte or binding fragment thereof in said conjugate is capable of binding said first analyte, and said second analyte or fragment thereof in said conjugate is capable of being bound by an antibody to said second analyte.
A kit for identifying in a sample the presence or level of a first analyte over that of a second analyte comprising a labeling means adapted to label the first analyte through a binding interaction that is inhibited by the second analyte, and directions for use of said kit.
A kit for identifying in a sample the presence or level of a first analyte over that of a second analyte comprising:
- (1) a mobile, labeled binding partner to one of the first analyte or the second analyte,
- (2) a conjugate between the second analyte and a binding partner to the first analyte;
- (3) an immobilized binding partner to the other of the first analyte and the second analyte;
- and
- (4) instructions for use of said kit.
A kit for identifying in a sample the presence or level of a first analyte over that of a second analyte comprising the components of
- 1) a mobile, labeled binding partner to one of the first analyte or the second analyte,
- (2) a conjugate between the second analyte and one of biotin and streptavidin, and
- (3) a binding partner to the first analyte conjugated to the other of biotin and streptavidin;
- (4) an immobilized binding partner to the other of the first analyte and the second analyte;
- and
- (5) instructions for use of said kit.
Dependencies are inferred from the claim text.