Redissolved peptide samples were then analyzed on a Dione Ultimate For in-gel digest experiments, the polymers were tested with peptide mixtures obtained from in-gel digests. In enrichment protocol, 4.0 mg of polymer was incubated with 200 µL of peptide mixture prepared in 90% MeCN + 0.1% TFA for 1 h., followed washing step using loading solution (200 µL) for 30 min. Both flow-through and washing fractions combined (FT+W). The elution was completed using first 50% MeOH + 0.1% TFA for 1 h. and then 80% MeOH + 0.1%