The PolyCAT A is made though a unique process for attaching Poly (aspartic acid) covalently to silica. Proteins elute from this polypeptide coating in sharp peaks with little tailing. Binding capacity and recovery are high as well. Operating conditions are similar to those used with other weak cation-exchange (WCX) materials (e.g. CM type). This cation exchange media can be used to separate by charge, or by polarity. Volatile mobile phases with high levels of organic solvents may be used.
Cation-Exchange of Peptides with Volatile Solvents
Ion-exchange is conveniently done with volatile solvents using PolyCAT A™, our weak cation-exchange (WCX) material. A gradient of acetic acid (HOAc) uncharges its carboxyl- groups, and even highly basic peptides are readily eluted. as in the example below. Strong cation-exchange (SCX) materials, such as our PolySULFOETHYL Aspartamide™, are generally too retentive to be used this way.