silica beads have been coated with a polysaccharide ( dextran or agarose ) , substituted by a calculated amount of positively charged diethylaminoethyl functions in order to neutralize the negatively charged silanol groups of silica and to facilitate the formation of a hydrophilic polymeric layer on the inorganic surface .
C0032594
polysaccharide
C0036681
agarose