Microarray slides
Carboxylate functionalized slides carry negative charge in buffer with pH greater than 4. They can covalently bind to biomolecules with primary amine groups after EDC/NHS activiation. This binding is more efficient than aldehide-amine binging. Polyethylene glycol (PEG) is monofunctional polymer that is well known for resisting non-specific adsorption. Polysaccharides (dextran and arginic acid) have long and bulky chains. Synthetic polymers (SP) have long and slim chains. SP type I is highly negatively charged polymer due to high density of carboxylate. SP type II is mildly negatively charged polymer. SP type III has long spacer arms that extend the carboxylate groups away from the main chains.
Amine functionalized slides carry positive charge in buffer with pH less than 10. They covalently bind to biomolecules with EDC/NHS activated carboxyl groups.
Epoxide functionalized slides covalently bind to thiol, amine and other nucleophilic groups. The reaction usually takes more than 6 hours.
Maleimide functionalized slides covalently bind to thiol groups (-SH). This reaction is very specific and fast.
Disulfide functionalized SPR chips covalently bind to thiol groups (-SH) through thio-disulfide exchange. After binding, the new formed disulfide bond can be broken by another thiol compound.
Ni chelated slides bind to his-tagged proteins.
UV-initiator modified slides covalently bind to all types of chemical groups under ultraviolet illumination. The reaction does not rely on any perticular groups. It takes about 15 minutes under 100W UV lamp.
Protein A immobilized slides bind to immunoglobulins, especially IgG.
Streptavidin immobilized slides bind to biotin-labeled biomolecules.
Nitrocellulose slides, general binding purpose
Hydrophobic slides bind to hydrophobic domines of proteins through hydrophobic interaction.
