The Establishment Of Total Protein Modified Reference Method And The Research Of Traceability Of The Clinical Measurement Results

ObjectiveTo establish the modified reference method of total protein while bath for 10mins in 37? by use of the biuret. And the uncertainty of measurements was assessed. The fresh frozen serum assigned by this reference method was used to calibrate routine testing system, and evaluated the traceability of the clinical measurement results.MethodsAccording to reference method and related files which recommended from United States disease control and Prevention Center (CDC), we established the total protein modified reference method. The condition of the modified reference method was changed to 37? temperature bath for 10mins. The imprecision, accuracy and the linear range were evaluated according to United States clinical and laboratory standard Association (CLSI) series file (EP5-A2, and EP15-A2, and EP6-A). Accuracy and imprecision of measurements were assessed by determining total protein in the sample A and B from RELA2O13 (2013 IFCC external quality assessment scheme for Reference Laboratories in Laboratory Medicine). And the certified reference material 909C was used to the correct evaluation experiment. The fresh serum specimens who no visible hemolysis, Icterus, celiac disease was used to the linear evaluation experiment. All of the component of measurement uncertainty for identification, quantification, and measurements of TP were evaluated. Using the reference method to assign fresh serum, and these fresh serum samples were applied to calibrate the TP results of 21 laboratories in Guangzhou. And the results were compered before and after calibration of determination of serum samples, then test the results by statistic method for comparability of assessment.ResultsThe precision of sample concentration of 55.48g/L and 88.68g/L were evaluated by use of the improved method, corresponding to the two concentration CV 0.56% and 1.23% respectively. The result of standard reference materials 909C was 70.21g/L, and the bias of the target is 1.76%. The high concentrations of serum for the analysis of linear measuring range limit for 128.69g/L. Two samples of the uncertainty of measurement results were 0.79% and 1.35% respectively. Assignment by the modified reference method than the serum calibration results compared with the reference method measurements, serum calibrator assigned values before calibration offset for an average of 2.08% after calibration is reduced to 0.5%.The samples serum 1 and 2 before the calibration offset for 1.2% and 2.28% respectively, calibrated drop-1.61%and-0.13%.ConelusionBasic operation refer to the CDC, established 37? temperature bath for 10mins total protein method, method of performance evaluation of precision and accuracy, linear and the uncertainty of measurement so reach the requirement within the measurement of total protein by improving biuret method performance. Use fresh serum calibration assignment of different laboratory measurements, accuracy and consistency of the laboratory results have greatly improved. This shows that the reference method value as fresh serum calibrator is calibrated is the effective way to realize traceability in laboratory, guarantee the comparability of results to achieve the results of different detection systems of traceability.