Compounds with NH2 radicals can be bound to COOH beads. After the COOH radicals on the bead surfaces are activated by NHS (N-Hydroxysuccinimide), the beads are mixed with compounds that have NH2 radicals. The NH2 radicals of the compounds form amide bonds with the COOH radicals.
A lineup of NHS beads with COOH radicals that were activated by NHS is also available. Binding of the compounds to the NHS beads does not require any other additives. Moreover, the reaction with compounds that have NH2 radicals occurs easily without any particular pretreatment, allowing compound-bound beads to be created.
When the binding reaction occurs, an amount of NHS equivalent to the bound compounds is separated from the beads. This separated NHS can be quantified by HPLC (high performance liquid chromatography) in order to quantify the amount of the compound which was bound to the beads.
Compounds with NH2 radicals can be bound to epoxy beads. Because epoxy radicals are highly active, they form a covalent bond with NH2 radicals under alkali conditions. Because epoxy beads produce almost no non-specific protein adsorption, it is not necessary to mask the remaining epoxy radicals.
|008||Immobilization of ligands (compounds with NH2 groups) on COOH beads|
|014||Immobilization of ligands (compounds with NH2 groups) on NHS beads|
|003||Immobilization of ligands (compounds with phenol groups or NH2 groups) on epoxy beads|