Validation of the biochemical method for determining the total cholesterol level in the samples of biological fluids as a base for providing the quality of dyslipidemia diagnostics
Authors: Misiurova S. V. , Svid N. O , Dobrova V. Ye , Otrishko I. A , Propisnova V. V. 
Published: April 2021

The main principles of creating a quality system in modern laboratory diagnostics are: standardization of laboratory processes by developing standard operating procedures; general quality management of laboratory research based on the development and implementation of the requirements of international standards (according to ISO 15189: 2015 "Medical laboratories. Basic requirements for quality and competence"); quality control of all stages of the laboratory process through the implementation of the validation procedure.
Aim. To develop a methodology for conducting validation procedures to assess the suitability of a biochemical method for determining the level of total cholesterol in biological fluids in the Clinical Diagnostic Laboratory of the Clinical Diagnostic Center of the NUPh.
Materials and methods. The object of the study was a standardized method for determining the concentration of total cholesterol. The method was validated using the “Cholesterol Reagent Set” test kit and the standard sample “Chemical control. Reagent kit. Level 1 ", manufactured by High Technology, Inc. (USA) with known concentration. The measurements were carried out on an Express Plus automatic biochemical analyzer manufactured by Bayer Corporation, Germany. When processing the research results, descriptive statistics were used and a number of statistical evaluations were carried out.
Results. A protocol and a validation report were developed at the Clinical Diagnostic Laboratory of the CDC NUPh to assess the suitability of the method for determining the concentration of cholesterol in biological fluids by the photometric enzymatic method on an automatic biochemical analyzer Express Plus (using reagents and control material manufactured by High Technology, Inc., USA). The validation characteristics of the method were determined: repeatability and reproducibility, correctness and uncertainty of measurements.
Evaluation of the internal laboratory repeatability and reproducibility of this technique indicates the absence of gross errors in the operation of the instrument and statistically important differences in measurements. The assessment of the correctness of the method (carried out using the control material) proved that the systematic error is not significant (according to a given acceptance criterion). The expanded uncertainty calculation showed that the obtained values ​​of the total cholesterol level can be considered accurate and reliable.
Conclusions. Validation of the method for determining total cholesterol in human blood by the photometric enzymatic method has proven that this method has performance characteristics that correspond to the regulated ones, meets the established criteria, and the parameters measured with it correspond to the proper ones.
Key words: validation, determination method, total cholesterol, repeatability and reproducibility, correctness and uncertainty of measurements