Although polymer 13 takes up a mass of water similar to that taken up by TENTA-GEL and ARGO-GEL ( data not shown), replacement of the DVB cross-linker in polymer 13 with α,ω-bis-styryl-pentaethylene glycol 4 gives polymer 15 and results in a polymer with a dramatically increased mass-water uptake that is far greater than those of both commercial resins. Similarly, replacement of the monostyryl-hexaethylene glycol monomer 7 in polymer 13 with monostyryl-poly ( oxyethyleneglycol)400 8 gives polymer 14, which again exhibits a incorporating a PEG chain into the cross-linker or increasing the PEG chain length of the monomer results in polymers with a greater mass-water uptake. In addition, since polymer 14 ( DVB cross-linker; monostyrylpoly ( oxyethylene glycol)400 monomre 8 ) takes up a greater mass of water than polymer 15 ( α, ω-bis-styryl-pentaeth-ylene glycol 4 cross-linker; monostyry-hexaethylene glycol 7) , the importance of the PEG length of the monomer appears to outweigh the effects of the small amount of cross-linker incorporated in gel-type supports such as these.