Patent ID: 8518714

Claim:
A blocked microparticulate binding surface for an affinity assay, comprising: a) a microparticle support surface; b) covalently coupled directly to the support surface, a plurality of support couplers, wherein less than a saturating amount of the support coupler is coupled with the support surface; c) a plurality of block copolymer molecules directly contacting the support surface, wherein the block copolymer molecules consist of a hydrophobic head group flanked by at least two hydrophilic tail groups having hydroxyl groups at the end of the tail, wherein the length of the two or more hydrophilic tails is independently about 2 to about 2.5 times the length of the hydrophobic head group, wherein the hydrophobic head group is adsorbed onto the surface of the support, and wherein the hydrophilic tail groups having hydroxyl groups that block passive protein absorption to the surface; and d) ligands coupled to the support coupler at a molar ratio of the ligand to the support coupler of not more than 5:1; wherein the support coupler is selected from the group consisting of BSA, ovalbumin, a fragment of BSA, a fragment of ovalbumin and a mixture thereof; and wherein the ligand is biotin.