Capillary isoelectric focusing (icIEF) bridging study between iCE3 and Maurice equipment

Monoclonal antibodies are inherently heterogeneous molecules due to post-translational modifications and degradation pathways that generate charge variants. As these variants can affect the isoelectric point (pI) of the molecule, reliable analytical techniques are required for their characterisation. Imaged capillary isoelectric focusing (icIEF) is commonly used to separate proteins according to their pI and assess charge heterogeneity.

This study compares the performance of the iCE3 and Maurice platforms for monoclonal antibody charge variant analysis and evaluates whether both systems can be used interchangeably while providing comparable results. The full application note details the methodology and study outcomes.

Method performance highlights

• Adalimumab was used as a model monoclonal antibody to compare charge variant analysis on the iCE3 and Maurice systems
• Repeatability and intermediate precision were evaluated across multiple analytical series performed by different analysts and on different days
• All predefined acceptance criteria were met for acidic isoforms, basic isoforms and main isoform quantitation on both systems
• A limit of quantitation study performed at 0.015 mg/mL generated signal-to-noise ratios ranging from 10 to 17
• Both platforms provided comparable precision and quantitation performance despite slight differences in electropherogram profiles

How this supports your charge variant analysis programme?

This bridging study demonstrates that equivalent icIEF results can be obtained across two different analytical platforms. The findings support the use of both systems within the same analytical environment while maintaining confidence in data comparability.

The study concludes that both systems can be used in a similar manner and that analytical methods can be transferred seamlessly from one platform to the other.

Use cases

• Charge variant analysis of monoclonal antibodies using icIEF
• Method precision assessment, including repeatability and intermediate precision studies
• Limit of quantitation evaluation during method validation or qualification activities
• Bridging and transfer of icIEF methods between analytical platforms