Comparison of a commercial method for total protein with a candidate reference method

Area of Science:

• Clinical Chemistry
• Analytical Biochemistry

Background:

• Standardization of total protein measurement is crucial for clinical diagnostics.
• The biuret method is a widely used assay for total protein determination.
• Evaluating automated analyzers against reference methods ensures accuracy and reliability.

Purpose of the Study:

• To standardize the biuret method for total protein measurement on the Boehringer Mannheim Diagnostics (BMD) Hitachi 717 Analyzer.
• To compare the BMD Hitachi 717 biuret method with a candidate reference method.
• To assess the accuracy, precision, and linearity of the BMD Hitachi 717 biuret method.

Main Methods:

• Comparison of the BMD Hitachi 717 biuret method with a candidate reference method.
• Analysis of 115 paired serum specimens.
• Statistical procedures for quantifying bias and linear regression analysis were employed.

Main Results:

• The Hitachi 717 biuret method demonstrated no significant bias compared to the reference method (z = -0.90).
• Acceptable correlation was observed between the two methods (r = 0.896).
• The method exhibited excellent precision (CV ≤ 2.14%) and linearity up to 15.0 g/dL.

Conclusions:

• The Boehringer Mannheim Diagnostics Hitachi 717 Analyzer biuret method is accurate and reliable for total protein measurement.
• The method is recommended for routine clinical use due to its convenience and accuracy.
• The standardization efforts confirm the suitability of the BMD Hitachi 717 for total protein analysis.