Capillary electrophoresis (CE) separates analytes inside a narrow fused-silica capillary under a high-voltage field, based on charge-to-size ratio. For research peptides, CE delivers very high resolution of charge variants and closely related impurities that can co-elute in chromatography.
Principles
In capillary zone electrophoresis, peptides migrate at rates set by their net charge and hydrodynamic size in the background electrolyte. Small changes — deamidation, oxidation, or a single charged residue difference — shift migration time measurably, making CE sensitive to modifications that matter in laboratory study design.
Laboratory Applications
- Purity assessment orthogonal to RP-HPLC
- Charge-variant profiling of synthetic peptide lots
- Identity confirmation by migration-time comparison with a reference standard
- Monitoring degradation products in stability and forced-degradation studies
Advantages and Limitations
CE uses nanoliter sample volumes, runs quickly, and resolves species HPLC may miss. Limitations include capillary conditioning requirements, buffer sensitivity, and lower preparative capacity — CE is an analytical, not purification, technique.
References
Kasicka, Electrophoresis reviews on peptide CE; USP general chapters on electrophoresis.
Disclaimer: For laboratory research education only. Not for human consumption / research use only. No medical, therapeutic, or dosing information is provided or implied.