Comparison of samples prepared in a filter plate to samples prepared in a collection plate. Artificially fouled PreDictor MabSelect SuRe was cleaned using: (1) PBS (20 mM phosphate, 0.15 M NaCl, pH 7.4) (control 1), (2) Proprietary CIP solution, (3) 0.15 M phosphoric acid, pH 1.6, (4) 6.0 M Guanidine hydrochloride, (5) 0.1 M NaOH + 1.0 M NaCl, (6) 0.1 M NaOH, (7) 0.5 M NaOH, (8) PBS, no fouling (control 2). The relative protein concentration on the resin was measured using chip electrophoreses (n = 4, mean ± SD).