Capillary zone electrophoresis determination of carbohydrate-deficient transferrin using the new CEofix reagents under high-resolution conditions.
Capillary zone electrophoresis (CZE) with a dynamic double coating based on the new CEofix reagents is shown to provide high-resolution separations of serum transferrin (Tf) isoforms, a prerequisite for the monitoring of unusual and complex Tf patterns, including those seen with genetic variants and disorders of glycosylation. A 50 microm I.D. fused-silica capillary of 60 cm total length, an applied voltage of 20 kV and a capillary temperature of 30 degrees C results in 15 min CZE runs of high assay precision and thus provides a robust approach for the determination of carbohydrate-deficient transferrin (CDT, sum of asialo-Tf and disialo-Tf in relation to total Tf) in human serum. Except for selected samples of patients with severe liver diseases and sera with high levels of paraproteins, interference-free Tf patterns are detected. Compared with the use of the previous CEofix reagents for CDT under the same instrumental conditions, the resolution between disialo-Tf and trisialo-Tf is significantly higher (1.7 versus 1.4). The CDT levels of reference and patient sera are comparable, suggesting that the new assay can be applied for screening and confirmation analyses. The high-resolution CZE assay represents an attractive alternative to HPLC and can be regarded as a candidate of a reference method for CDT.
Joneli
Jeannine
J
Department of Clinical Pharmacology, University of Bern, Murtenstrasse 35, CH-3010 Bern, Switzerland.
Lanz
Christian
C
Thormann
Wolfgang
W
D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D020033:Protein Isoforms / Q000032:analysis / Q000097:blood; D015203:Reproducibility of Results; D014168:Transferrin / Q000031:analogs & derivatives* / Q000032:analysis
D007202:Indicators and Reagents; D020033:Protein Isoforms; D014168:Transferrin; C056759:carbohydrate-deficient transferrin