Chromatin glycoproteins recognized by Concanavalin A have been isolated from pig liver, kidney and heart by the use of immobilized lectin. Two groups of proteins differing in affinity for DNA have been analysed. Glycoproteins are mainly present in the group of proteins which are tightly bound to DNA. Mono and bidimensional electrophoretic patterns of total tightly bound proteins reveal a similarity among the three organs examined, while the corresponding patterns of the glycoproteins are typical for each organ. The tissue specificity of chromatin glycoproteins, together with their capability to interact not only with DNA but possibly also with other nuclear components, suggest a role for these proteins in the mechanism of genome expression.