Patent ID: 6890765

Claim:
A method of preparing particles for immunoassays, comprising: reacting particles comprising carboxylate groups with N-hydroxysuccinimide or N-hydroxysulfosuccinimide and with a carbodiimide coupling reagent to provide activated particles comprising succinimide ester groups; contacting said activated particles with antibodies to provide sensitized particles comprising covalently bound antibodies and residual succinimide esters; and treating said sensitized particles in an aqueous mixture with an amine compound selected from the group consisting of 2,2′-(ethylenedioxy)bisethylamine and 4,7,10-trioxa-1,3-tridecanediamine wherein the treatment results in the reaction of the succinimide ester groups with the amine functionality of the amine compound to form an amide linkage.