Binding surfaces for affinity assays

A method of preparing a non-saturated assay binding surface, comprising:

• a) combining support couplers and ligands at a ratio of ligand to support coupler selected so as to result in a mixture of ligand::support coupler complexes;
• and,
• b) covalently attaching the ligand::support coupler complexes to an assay support so as to yield a non-saturating density of ligand::support coupler complexes.

A population of dispersed microparticles, wherein the microparticles are exposed to a dispersant, the dispersant comprising a block copolymer having a hydrophobic head group flanked by at least two hydrophilic tail groups.

A method of preparing a non-saturated assay binding surface, comprising:

• a) preparing a mixture of analyte-associating-moieties and space-filling moieties, wherein the analyte-associating-moieties associate, either directly or indirectly, with an analyte of interest, and the space-filling moieties do not associate, either directly or indirectly, with an analyte of interest;
• and,
• b) exposing the mixture to an assay support such that the analyte-associating-moieties and the space-filling moieties couple with the assay support and form a non-saturated assay binding surface that is non-saturated with respect to the amount of analyte-associating-moieties coupled with the assay support.

A method of making a blocked assay binding surface, comprising

• coupling an assay support with a support coupler to yield a binding surface,
• contacting the binding surface With a block copolymer, wherein the block copolymer comprises a hydrophobic head group flanked by at least two hydrophilic tail groups.

An affinity assay employing a non-saturated assay binding surface, the affinity assay comprising

• contacting a non-saturated assay binding surface with an analyte, wherein the non-saturated assay binding surface comprises a support coupler, a ligand, a ligand binder, and an analyte-specific capture moiety, and
• detecting the binding of the analyte with the non-saturated assay binding surface.

A non-saturated assay binding surface, comprising:

• a) an assay support;
• and
• b) at least one ligand, wherein less than a saturating amount of the ligand is coupled with the assay support.