Covalent attachment of specific binding members to a solid phase with two bifunctional reagents and a dithio compound

摘要

A specific binding member such as an antigen or antibody is immobilized by covalent attachment to a solid phase such as a latex microparticle. The solid phase is reacted with a heterobifunctional or homobifunctional coupling agent to form a complex that is then reacted with a dithiol compound to form a thiolated solid phase. A specific binding member is reacted with the coupling agent to form a complex which is then reacted with the thiolated solid phase to link the specific binding member to the solid phase through thioethers. Alternatively, the dithiol compound may be reacted with the specific binding member/coupling agent complex to form a thiolated complex that is reacted with the solid phase/coupling agent complex. The coupling agent may contain a spacer. In another embodiment, the solid phase is reacted with a disulfide compound to form a complex and the complex is reacted with a reductant to form a thiolated solid phase which is reacted with a specific binding member/coupling agent complex. The immobilized specific binding member can be used in diagnostic binding assays, and it has increased sensitivity, specificity and stability, while requiring the use of less specific binding member.