Abstract: Methods and compositions for detecting and quantifying cytokines are provided. The disclosed assays have reduced assay interference relative to commercially available assays and/or a control assay. The interference can be cytokine dependent, cytokine independent, or both. One embodiment provides an IL-33 immunoassay that reduces assay interference caused by endogenous soluble IL-33 binding molecules present in the sample. Exemplary soluble IL-33 binding molecules include, but are not limited to anti-IL-33 antibodies, soluble ST2 receptor, and serum components. In some embodiments a blocking agent is added to the sample to reduce, inhibit, or block IL-33 complexes in the sample from reforming after acid dissociation of the IL-33 complexes in the sample. In one embodiment, the blocking agent and the detection reagent do not compete for binding to IL-33.

Abstract: Methods and compositions for detecting and quantifying cytokines are provided. The disclosed assays have reduced assay interference relative to commercially available assays and/or a control assay. The interference can be cytokine dependent, cytokine independent, or both. One embodiment provides an IL-33 immunoassay that reduces assay interference caused by endogenous soluble IL-33 binding molecules present in the sample. Exemplary soluble IL-33 binding molecules include, but are not limited to anti-IL-33 antibodies, soluble ST2 receptor, and serum components. In some embodiments a blocking agent is added to the sample to reduce, inhibit, or block IL-33 complexes in the sample from reforming after acid dissociation of the IL-33 complexes in the sample. In one embodiment, the blocking agent and the detection reagent do not compete for binding to IL-33.

Abstract: The inventions provide immunoassays for reducing the effects of interference in the detection and quantification of analytes, including but not limited to cytokines, enzymes, antibodies, and others by acidifying samples and allowing for binding of the analytes and corresponding capture reagents in the acidified samples without neutralization.

Abstract: Methods and compositions for detecting and quantifying cytokines are provided. The disclosed assays have reduced assay interference relative to commercially available assays and/or a control assay. The interference can be cytokine dependent, cytokine independent, or both. One embodiment provides an IL-33 immunoassay that reduces assay interference caused by endogenous soluble IL-33 binding molecules present in the sample. Exemplary soluble IL-33 binding molecules include, but are not limited to anti-IL-33 antibodies, soluble ST2 receptor, and serum components. In some embodiments a blocking agent is added to the sample to reduce, inhibit, or block IL-33 complexes in the sample from reforming after acid dissociation of the IL-33 complexes in the sample. In one embodiment, the blocking agent and the detection reagent do not compete for binding to IL-33.