1.2 Proteins different in size can be separated by gel-filtration(size-exclusion, molecular sieve) chromatography. 1. 2.1 Samples are applied to columns of porous beads(made of insoluble but highly hydrated polymers like dextran, agarose, and polyarylamide)1.2 Proteins different in size can be separated by gel-filtration (size-exclusion, molecular sieve) chromatography. 1.2.1 Samples are applied to columns of porous beads (made of insoluble but highly hydrated polymers like dextran, agarose, and polyarylamide)