BioPharmaSpec offers Imaging Capillary Isoelectric Focusing (icIEF)and Ion Exchange Chromatography as methods for determination of charge isoforms.

Imaging Capillary Isoelectric Focusing (icIEF)

Our dedicated iCE3 system achieves accurate and reproducible separation and quantitation of the pI isoforms of your biopharmaceutical, providing you with valuable data on charge variants due to PTMs including phosphorylation, sulfation and glycoforms with partial sialylation, or process-related impurities such as deamidations.

Imaging capillary IsoElectric Focusing (icIEF) is our preferred method for the analysis of the isoforms of biopharmaceuticals. icIEF is free solution IsoElectric Focusing in a capillary column that detects focused protein zones using a whole column UV absorption detector. This method avoids disturbing these focused zones and is unique in that it has the comparable resolution of traditional gel IEF while incorporating the advantages of a column-based separation technology, including quantitation and automation.

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Ion Exchange Chromatography

Read more about this technique at our chromatography page.