Effect of HbS in the determination of HbA2 with the Biorad Variant II analyzer

Objectives: The effect of the presence of HbS in the determination of HbA2 using the Biorad Variant II analyzer. Design and methods: The effect of HbS presence in the samples was quantified using the HELENA SAS-MX alkaline gel electrophoresis kit as the reference method. Results: The %HbA2 values from the Variant II analyzer and the HELENA SAS-MX alkaline gel electrophoresis kit show a good linear correlation in the absence of HbS. A strong positive bias in the %HbA2 values from the Variant II is apparent in the presence of HbS in the samples, when compared to the alkaline electrophoresis gel. Conclusion: The Variant II analyzer gives reliable results for %HbA2 determination when no HbS is detectable in the samples. When HbS is present, the gel electrophoresis method gives more accurate results.