Ion-exchange chromatography separates peptides based on charge differences and is used when a different / orthogonal separation mechanism is desired vs the more traditional use of reversed-phase chromatography.
Separations are most commonly performed using a gradient of increasing salt concentration with the smaller, less charged peptide species eluting prior to the longer peptide fragments. Unlike reversed-phase peptide separtions, eluent pH can significantly affect the separation so method development is required in order obtain satisfactory chromatography.
As with other bioseparations, use smaller particle size, UPLC/UHPLC offerings provide superior component resolution and in less time compared to our HPLC-based columns.
Protein-Pak HR Ion-Exchange Glass Columns
Protein-Pak HR packing materials are based on rigid, hydrophilic, polymethacrylate particles with large 1000 Å pores. The naturally hydrophilic polymer reduces non-specific adsorption, resulting in quantitative recovery of protein mass and bioactivity. These packings are compatible with buffers in the pH range 2-12, and will withstand exposure to caustic solutions.
Protein-Pak HR ion exchangers are available with a:
The Protein-Pak HR 8 µm and 15 µm packing materials are available prepacked in Waters Advanced Purification (AP) glass columns. These columns are compatible with a variety of analytical and preparative LC instrumentation.
BioSuite Ion-Exchange HPLC Columns
BioSuite Ion-Exchange Columns include four separation chemistries -- SP strong and CM weak cation-exchangers and Q strong and DEAE weak anion-exchangers -- bonded to a pH stable (pH 2–12), methacrylic ester-based polymeric resin. This broad choice of separation chemistries provides chromatographers with the flexibility to develop methods that separate proteins or peptides based on subtle charge differences. Selected BioSuite ion-exchange columns are also offered with PEEK hardware as well as in 21.5 mm I.D. for lab-scale preparative applications.