Abstract: The present invention relates to a microcarrier onto the surface of which a cationic compound has been immobilised via a guanidine group. The microcarrier is capable of attachment of cells, e.g. via charge-based interaction, and is advantageously used as a support in the culture of cells. Said compound may comprise one or two amino acids, such as arginine (Arg) or a dipeptide. The invention also relates to a method of preparing a polycationic microcarrier, which method comprises to immobilise a compound that comprises at least one guanidine group to an epoxide-activated substrate.