Abstract: A hydrophobic crosslinked copolymer havng a pendant group selected from ##STR1## wherein R.sup.1 represents at least one hydrophobic group having a hydrophobic fragmental constant of at least 1.5, which copolymer has a high crosslinking monomer units content, a specific surface area and a specific acetonitrile regain value. The hydrophobic crosslinked copolymer has a high rigidity as well as an excellent mechanical strength and an excellent chemical stability so that the copolymer is useful as a packing for liquid chromatography, particularly reversed phase partition chromatography. This hydrophobic crosslinked copolymer can be advantageously produced by a method in which a crosslinked copolymer having a side chain of small length is first produced, and then a substitution reaction to introduce a hydrophobic group of large length is effected with respect to the side chain of small length.

Abstract: A totally porous activated gel which comprises a matrix of a totally porous crosslinked copolymer comprising as main components vinyl alcohol monomer units and crosslinkable monomer units and having a specific surface area of 5 to 1000 m.sup.2 /g and an reactive group linked to said matrix by a covalent bond. The present activated gel is very useful for effectively separating bio-substances due to the peculiar behavior of the reactive group of the activated gel. The activated gel is rigid, and is excellent in mechanical strength, resistance to chemicals, high pH, low pH, high temperature and low temperature, and is very effective in specific adsorption of bio-substances. The activated gel can be subjected to freeze-drying sterilization, heat sterilization and radiation sterilization, so that it can be utilized for the medical treatment by extracorporeal perfusion of, for example, blood.