Capillary isoelectric focusing (cIEF)
Coriolis Pharma is specialized in providing stability indicating protein analytical methods, including capillary isoelectric focusing for monitoring charge heterogeneity e.g. protein deamidation.
Capillary isoelectric focusing (cIEF) is a high-resolution analytical technique that allows the separation of protein/peptide mixtures, protein glycoforms and other charge variants, based on their isoelectric point (pI). In order to establish a pH gradient through the capillary, which allows protein/peptide separation, a voltage is applied to the anolyte and catholyte tanks (filled up with phosphoric acid and sodium hydroxide, respectively).
When compared to conventional isoelectric focusing (IEF) in gels, cIEF allows for higher resolution, faster sample analysis and has an approximately 10 fold lower limit of detection. In addition, with cIEF the conventional one-point detection is overcome by continuous detection over the whole capillary, allowing real-time observation and preventing sample degradation (due to sample mobilization) before detection.
In our laboratories cIEF is typically used for monitoring charge heterogeneity as well as oxidation and deamidation analysis of several therapeutic (glyco)proteins, and in the context of product characterization or comparability studies.
We operate iCE280 and iCE3 systems from Protein Simple.