A clean-in-place procedure involving storage in 0.5M-NaOH for several hours has been found effective in the regeneration of process-scale columns (25 1) of Express-Ion ion-exchange celluloses following preparative loadings (2–9 kg) of a hen egg-white protein feedstock. These conditions have been demonstrated to provide simultaneous sanitization of the media following a gross microbial challenge, as indicated by decreased bioburden and endotoxin levels. We have developed an ion chromatography procedure for detecting and quantitating potential hydrolysis products originating from the functional groups bonded to anion and cation-exchange media. Using these techniques we demonstrate no detectable leakage of functional groups from the ion-exchange celluloses during the bed regeneration process. There was no significant loss of glucose from the matrix during this procedure.