Enzyme immobilization by entrapment.

Entrapment methods of immobilization are mostly used in cell immobilization procedures, but have found some application with enzymes, particularly when the enzyme is essentially a dead cell or crude homogenate(1). In theory the entrapped enzyme is not attached to the polymer; its free diffusion is merely restrained. In practice, however, some or all of the enzyme may be an integral part of the polymer matrix; for example, chain termination in polyacrylamide gel formation may occur onto the enzyme (see also ref. 2).