Hydrocoating Solid Phase Chemical Coupling Techniques

The method-Hydrocoating-for covalent immobilization of biomolecules wasstudied. Soluble dextran was handed by 2,2,2-triflourethanesulphoyl chloride or p-toluensulfonyl chloride, and polyvinyl alcohol (PVA) or dextran was oxidized bysodium periodate leading to activation of hydroxyl groups on the dextran or PVApolymer. The activated dextran or PVA molecule was immobilized on a surfacecontaining amino groups leaving a sufficient number of active groups for secondarybinding of biomolecules. The coating conditions for activating dextran or PVA werestudied and the best results obtained are as follows: â‘ the concentrations ofactivated PVA by oxidation, activated dextran by oxidation, activated dextran withtrifiourethanesulphoyl chloride and activated dextran with p-toluensulfonyl chloridewere 2mg/ml, 2mg/ml, 0.02mg/ml and 0.05mg/ml respectively, â‘¡ PVA or dextranwas oxidized to the degree of l .5 (the molar ratio between sodium periodate and theOH-group on PVA or dextran); â‘¢ the amount of PEG in TSH coating buffer wasl5%; â‘£ the solutions of ethanolamine and NaBH4 were selected as the blockingbuffer for hydrocoating. The tubes activated by hydrocoating were better than thosedealt with passive adsorption in surface antibody bind capacity nonspecific bindingand durability. Especially, hydrocoating could efficiently immobilize the smallmolecule (T4), Which was only bound weakly by passive adsorption.