Method of chromatography in which molecules that are negatively charged are selectively released from stationary phase into the positively charged molecules in mobile phase is termed as: (A) Affinity chromatography, (B) Ion-Exchange chromatography, (C) Adsorption chromatography, (D) Size-Exclusion chromatography
Answer is B. In ion exchange chromatography, charged protein replaces the respective ion on exchange resin. For example, in DEAE cellulose chromatography (anion exchange), negatively charge proteins bound to DEAE resin (stationary phase) and release Cl- from it.