Objective: Transferrin isoform analysis is performed for diagnosis of congenital or acquired defects in protein glycosylation. The reference method for transferrin isoform analysis is isoelectric focusing electrophoresis. The objective of this study has been to perform transferrin isoform analysis using two different electrophoresis systems in our laboratory and to compare the two systems.

Materials and Methods: The isoelectric focusing electrophoresis of transferrin isoforms was performed by "Multiphor II" ve "PhastSystem". The analytical performance was evaluated using a commercially available quality control material at two different levels. The two systems were compared with regression analysis with blood samples obtained from 40 patients.

Results: In isoelectric focusing method by "Multiphor II" system the coefficients of variation (CV) were determined to be < 3.5 % for within run (n=7) and < 7 % for between run (n=20) imprecision considering di- and tetrasialotransferrin isoforms in two levels of control material. The same values for "PhastSystem" were < 7% (n=8) and < 6% (n=10) respectively. In IEF with “PhastSystem”, disialotransferrin isoforms were determined to be 9.69% and 9.27% higher while tetrasialotransferrin isoforms were determined to be 1.33% and 2.15% higher compared to “Multiphor II” at low and high levels of control material respectively. In the regression analysis (n=40) coefficients of correlation for dive tetrasialotransferrin isoforms were determined to be 0,85 ve 0,64 respectively.

Conclusion: Transferrin isoform analysis with isoelectric focusing electrophoresis can be performed precisely with similar accuracy with both “Multiphor II” and “PhastSystem”. In routine laboratory practice “PhastSystem” may be preferred due to its speed.