Cation Exchange

Cation exchange chromatography is performed with either a strong cation exchange column, containing a sulfonium ion, or with a weak cation exchanger, having usually a carboxymethyl (CM) functional group. A counter ion, often Na+ maintains electroneutrality.

In ion exchange chromatography the pH of the mobile phase buffer must be between the pI or pKa of the charged molecule and the pKa of the charged groups on the solid support. For example, a molecule with a pI of 8.2 is run in a mobile phase buffer at pH 6.0 with the solid support pKa at 1.2 in cation exchange chromatography.

Specialty columns:

  • Organic acids by ion-exclusion (SCX)


Nonporous TSKgel CM- and SP-STAT columns are ideal for fast, highly efficient analysis of biomolecules.

  • Pore structure and bonding chemistry of TSKgel BioAssist S provides high capacity for large proteins.
  • TSKgel BioAssist columns are packed in PEEK hardware. Other columns are available in glass and stainless steel for anlytical, semi-preparative and preparative work.
  • Binding capacity  for small to medium size proteins on TSKgel DEAE-3SW is approximately double that of the 5PW packings due to the smaller pore size and larger surface area.
  • TSKgel SP-5PW column available in 2 mm ID format.

Strong Cation Exchange





Weak Cation Exchange