ABSTRACT
Objective To investigate how the clinical laboratory conducting the verification of analytical measurement range (AM R) of quantitative items detected by the biochemical analyzer according to the requirements of the international standards by verifying the serum creatinine AMR for ensuring the accuracy and reliability of detection results .Methods The enzyme method was adopted to detect the 7‐concentration levels test specimens of CAP linear range proficiency test on the Roche Cobas 501 biochemical analyzer .These 7 specimens target values covered the low ,middle and high values of creatinine AMR marked by the manufacturer′s instructions .Each specimen was detected twice and the mean value was taken ,then the bias between the mean value and target value was calculated .In addition ,referring to the requirements of CLSI guiding document EP6‐P ,the patients′fresh serum contai‐ning high value creatinine was collected ,then mixed with certain proportion and centrifuged .The mixture concentration was calcu‐lated and served as the high value specimen(H) ,and the low value specimen was obtained by the same treatment .Then the high and low value specimens were dispensed with the relations of 5L ,4L+1H ,3L+2H ,2L+3H ,1L+4H and 5H and formed the series specimens .The creatinine levels in each specimen was detected on the Roche Cobas 501 biochemical analyzer ,each specimen was de‐tected 4 times .The obtained data were performed the regression analysis .Results The bias of 7‐level CAP specimen and target val‐ue was less than the allowable error ± 7 .5% [(1/2 × TE)% ] set by the clinical laboratory of the Beijing Sanfine Hopsital .The re‐gression equation of fresh mixed serums from patients was Y =0 .988 6X+16 .614 ,b=0 .988 6 ,between 0 .97 -1 .03 ,intercept a and 0 ,ta 0 .05 ,which showed no significant difference between intercept and 0 ,the regression line was through 0 point in fact .Conclusion The verification of creatinine AMR marked by the manufacturer′s instructions is passed ,which can be adopted by the clinical laboratory .