A self-established method for the quantitative determination of plasma free hemoglobin utilizing the hemolysis index of Siemens ADVIA 2400 chemistry system

Objectives: The significance of the quantitative hemolysis index (HI) obtained from the Siemens ADVIA 2400 Chemistry System remains undisclosed. This study aims to establish a method utilizing HI of Siemens ADVIA 2400 Chemistry System for the quantitative determination of plasma free hemoglobin (fHb). Materials and Methods: The performance of the self-established method was assessed following Clinical and Laboratory Standards Institute protocols, which included detection capability, linearity, imprecision, and trueness, using materials derived from residual whole blood samples. Statistical Analysis: The analysis of variance was performed using Microsoft Excel, and least-squares linear regression analysis was conducted using MedCalc (Version 20.216). A significance level of P < 0.05 was considered. Results: The repeatability and within-laboratory precision both exhibited a coefficient of variation below 1%. The limit of blank was determined to be 0.005 g/L, while the lower limit of detection and lower limit of quantification were found to be 0.050 g/L and 0.085 g/L, respectively. Our self-established method for determining plasma fHb demonstrated linearity across the entire assay range of 0.085~25.2 g/L with an excellent correlation coefficient (R 2 = 0.9998). In the method comparison study between Siemens ADVIA 2400 and Sysmex XN-1000, our results indicated a slight bias, with only 5% (2/40) of the plots falling outside the 95% confidence interval. This suggests a high level of agreement observed between these two devices. Conclusions: The self-established method was evaluated as a reliable assay with robust performance for quantifying minute quantities of plasma fHb in the ADVIA 2400 chemistry system. Calibration for the HI was deemed necessary when determining plasma fHb.