Proteins are an extremely important class of (bio)macromolecules as virtually no process within cells occurs without their direct involvement.As a consequence, their analysis is of paramount relevance in fields, such as proteomics, food chemistry, pharmaceutical and life-sciences.One of the most common approaches to determine protein structure, as well as to identify them, consists in (1) digesting them and (2) analyzing the resulting peptides.This idea is at the heart of the "bottom-up" approach to proteomics.Protocols include proteolysis (digestion) in a solution containing both a proteolytic enzyme, e.g.trypsin, and the protein(s) of interest.When done in solution, the proteolysis must generally be carried out with only a small amount of the soluble enzyme to avoid autodigestion.Therefore, the process is slow, requiring several hours to complete.Some of the problems typical of protein digestion in solution can be overcome with use of the enzyme immobilized on a solid support.This approach enables a high localized concentration of the enzyme and a significant acceleration of the digestion without any appreciable autodigestion due to the site isolation effect [1].