On-line enzymatic digestion in separation-detection methods

Apparatus and methods are disclosed for digesting a biopolymer in a medium. The medium is disposed adjacent a wall of a hollow element wherein at least a portion of the wall is porous. The medium is then exposed to digestion conditions to cleave the biopolymer into fragments. The fragments are permitted to permeate through the wall of the hollow element. In some embodiments a surface of a wall of the hollow element comprises a digestion agent. In some embodiments the hollow element is disposed within a hollow liner. For analysis and identification purposes, the fragments may be separated and/or detected.