Determination of total protein content in biologicals using biuret method

Abstract

Biuret is one of the methods of protein quantification with many advantages: fast, simple, accurate, suitable for samples with high protein content and purity. In order to convert the method of determining total protein content in biological products with high protein content from Lowry to Biuret method, from April to December 2018, at the Department of Physical Chemical – National Institute for Control of Vaccine and Biologicals, we have conducted an experimental laboratory research methods to evaluate the suitability of the procedure for determining total protein content by Biuret method on two biologicals: IV Globulin and SAR with satisfactory accuracy, precision, robustness, specificity, linearity, limit of quantification LOQ = 0,613 mg; and evaluate the uncertainty (U) of method as required by ISO/IEC 17025:2017, the uncertainty of the IV Globulin sample is 1.78 mg and the SAR sample is 1.85 mg.