Selection of migration parameters for a highly reliable assignment of bands of isoforms of erythropoietin separated by capillary electrophoresis

• Published in: Electrophoresis Vol. 25; no. 10-11; pp. 1569 - 1579
• Main Authors: Lacunza, Izaskun, Lara-Quintanar, Pilar, Moya, Galina, Sanz, Jesus, Diez-Masa, Jose C., de Frutos, Mercedes
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.06.2004; WILEY‐VCH Verlag
• Subjects: Capillary electrophoresis; Darbepoetin alfa; Electrophoresis, Capillary; Epoetin Alfa; Erythropoietin; Erythropoietin - analogs & derivatives; Erythropoietin - chemistry; Humans; Migration index; Numerical Analysis, Computer-Assisted; Protein Isoforms - chemistry; Recombinant Proteins
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.200305831

Capillary zone electrophoresis of samples of recombinant human erythropoietin is performed. An in‐house computer program is developed to compare the reliability of different migration parameters to assign the close migration bands of isoforms of erythropoietin. The migration time relative to the electroosmotic flow marker and the effective electrophoretic mobility are selected as the most accurate parameters. Percentages of correct assignment of bands higher than 99% are obtained with these parameters even when changes in operational factors are introduced. The chosen parameters have been applied to assign bands of isoforms in commercial samples of α‐ and β‐epoetin. The same capillary electrophoresis method has been applied to separate bands of isoforms of an erythropoietin analogue, darbepoetin α, the novel erythropoiesis‐stimulating protein.