Disclosed are proteins which are covalently bound to a solid support at a first temperature where they have a first configuration, and then biomolecules are attached to the bound proteins at a higher temperature at which the proteins have more exposed functional groups, each such group being capable of covalently bonding to a biomolecule. The biomolecule can be, for example, a nucleic acid, including an amine functionalized oligonucleotide. The proteins can include, BSA (Bovine Serum Albumin) which can be bound using a reaction with the surface of a tosyl-activated microparticle.