We systematically evaluated MZE against Maurice icIEF across 9 molecules representing multiple therapeutic modalities. For each molecule, unstressed reference and time-course stressed samples were analyzed. Analytical performance metrics for MZE were assessed including linearity, accuracy, repeatability, intermediate precision, and sample stability. Comparisons also included a native separation orthogonal technique (IEX) for selected samples. Relative abundances of main, acidic, and basic variant groups were determined and compared across platforms using linear regression (R2). MZE captured charge-variant trends consistently with icIEF across diverse molecules (pI range 7.0–9.0). Strong correlations (R2 > 0.80) were observed for variant groups that exhibited substantial percentage changes; lower R2 values were mainly associated with variant groups showing minimal change ( <4% absolute change), limiting dynamic range for regression. The LabChip GXII MZE platform provides a rapid, sample-sparing alternative that reliably reproduces charge-variant trends observed by icIEF and IEX.
Learning Objectives:
Microchip zone electrophoresis (MZE) on the LabChip GXII Touch system offers rapid separations (<2 minutes) and low sample consumption, but direct, comprehensive comparisons to icIEF are limited.
MZE captured charge-variant trends consistently with icIEF across diverse molecules (pI range 7.0–9.0).
Strong correlations (R2 > 0.80) were observed for variant groups that exhibited substantial percentage changes; lower R2 values were mainly associated with variant groups showing minimal change (<4% absolute change), limiting dynamic range for regression.
. MZE assay performance for mAb2 showed good linearity (R2 > 0.90 across all the variants), acceptable accuracy (% recovery generally 80–121%), and repeatability and intermediate precision within acceptable %RSD ranges (main: ≤1.9% RSD).
Labeled samples were stable at ambient conditions for several hours with minimal change (<0.3%).
