Abstract: Provided herein are immunofluorescence assays that do not use an intensely colored lipophilic dye, and that result in a significant reduction of fluorescence due to aldehyde fixation, collagen, elastin, and/or red blood cells. In certain embodiments of the present invention, a two-step treatment of the tissue is contemplated that leads to the incorporation of reduced heteropoly acids or salts thereof (e.g., phosphomolybdate species) in the tissue. This reagent binds tightly to hydrophilic regions of the tissue and effectively quenches the fluorescence in those regions. In doing so, the overall signal-to-noise ratio for the immunofluorescence assay is increased.

Abstract: Provided herein are immunofluorescence assays that do not use an intensely colored lipophilic dye, and that result in a significant reduction of fluorescence due to aldehyde fixation, collagen, elastin, and/or red blood cells. In certain embodiments of the present invention, a two-step treatment of the tissue is contemplated that leads to the incorporation of reduced heteropoly acids or salts thereof (e.g., phosphomolybdate species) in the tissue. This reagent binds tightly to hydrophilic regions of the tissue and effectively quenches the fluorescence in those regions. In doing so, the overall signal-to-noise ratio for the immunofluorescence assay is increased.

Abstract: The present disclosure generally relates to methods for detecting one or more analytes in a sample using immunoassays. In some embodiments, the disclosure provides methods that include quenching the free secondary antibody with a fractionated serum composition. In some other aspects, the disclosure provides systems and kits suitable for carrying out the foregoing methods and any embodiments thereof.

Abstract: An enhanced labelling complex for localizing markers on a prepared tissue section is disclosed. The complex includes both avidin components and biotinylated macromolecular components at a ratio preselected to provide a complex which is sufficiently large to include a large number of labels, and sufficiently small to penetrate the tissue section. The markers are localized by first introducing a biotinylated link into the tissue section and thereafter exposing the section to the labelling complex.