A new method for preparing adsorbents for biospecific affinity chromatography is described. Bisoxiranes (e.g. 1,4-butanediol diglycidyl ether) have been used for the introduction of reactive oxirane groups into agarose, and for simultaneous stabilization of the gel by cross-linking. Optimal conditions for the activation and subsequent coupling of proteins, peptides and aliphatic and aromatic amines have been evaluated. Fractionation of different forms of trypsin on soya bean trypsin inhibitor agarose is described in order to illustrate the use of oxirane-agarose in biospecific affinity chromatography.