A Comparative Study of Serum Albumin Estimation: BCP and BCG Dye Binding Methods vs. Capillary Electrophoresis

Abstract

Dye binding methods remain popular for serum albumin estimation due to their practicality and affordability. BCG and BCP methods, the two dye binding techniques are known to yield discordant results and there is a lack of consensus in the literature necessitating further investigation and attention. To compare the BCG and BCP methods, a method comparison study was carried out against the CZE method serving as the reference. The albumin concentration of 47 blood samples was measured using the three methods. One-way ANOVA test followed by a post-hoc Tukey HSD test for pairwise discrepancies, independent sample t-test, Pearson Correlation, and Bland-Altman plots were employed to compare and evaluate the correlation and agreement between the methods. No significant difference was observed in measurements between the CZE (M = 35.72 g/L, SD = 7.12 g/L) and BCP (M = 36.4 g/L, SD = 7.08 g/L); t (88) = -450, p = 0.654 (p>0.05) methods. Mean difference between BCG (M = 40.28 g/L, SD = 5.53 g/L) and CZE methods was 4.56 g/L, demonstrating significance; t (88) = -3.39, p = 0.001 (p<0.05). Both BCG (r=0.875, p<0.001) and BCP (r= 0.910, p<0.001) methods showed a significant positive correlation with the CZE method while the BCP method had the strongest.  Bland Altman analysis revealed a bias of 0.67 g/L, (95% limits of agreement, -5.00 g/L to 6.56 g/L) between the BCP and CZE methods. The BCG method showed a bias of 4.56 g/L (95% limits of agreement, -2.34 g/L to 11.46 g/L) versus the CZE method. This study concludes that the BCP method agrees more closely with the CZE method. The BCG method overestimates albumin in serum in comparison to the CZE method (positive bias), more so than observed with the BCP method.

KEYWORDS:     Albumin, HSA, Dye-binding, BCG, BCP, CZE