In biotechnology enzymes and cells have been immobilized for several years. A special kind of immobilization is the entrapment of biocatalysts. Hollow beads on the basis of sulfoethyl cellulose (SEC) are expected to be advantageous for a variety of applications. This study provides a thorough description of the preparation of hollow beads with good mechanical stability on the basis of polyelectrolyte polyelectrolyte complexes of SEC as polyanion for the encapsulation of biocatalysts and other materials under moderate conditions.