Characterization and Validation of the LT-SYS Copper Assay on a Roche Cobas 8000 c502 Analyzer.
OBJECTIVE
Validation of the LT-SYS quantitative in vitro copper assay on a Roche Cobas 8000 c502 analyzer and comparison with a BIOMED assay on a Roche Cobas Mira analyzer.


METHODS
Imprecision and bias were quantified at different concentration levels (serum and plasma) over a 20-day period. Linearity was assessed covering a range from 4.08 µmol/L to 33.8 µmol/L. Limit of blank (LoB) and limit of detection (LoD) were established based on a total of 120 blank and low-level samples. The method comparison was based on 58 plasma samples.


RESULTS
Within-run imprecision ranged from 0.7% to 1.2% and within-laboratory imprecision from 1.4% to 3.3%. Relative bias for the 2 serum pools with known target values was less than 2.5%. The assay did not deviate from linearity over the tested measuring range. LoB and LoD were 0.12 µmol/L and 0.23 µmol/L, respectively. The method comparison revealed an average deviation of 11.5% (2.016 µmol/L), and the linear regression fit was y = 1.464 + 0.795x.


CONCLUSIONS
The LT-SYS copper assay characterized in this study showed a fully acceptable performance with good degrees of imprecision and bias, no deviation from linearity in the relevant measuring rangem, and very low LoB and LoD.
Zentrallabor, Department of Laboratory Medicine, University Hospital Halle, Halle (Saale), Germany bernhard.kraus@uk-halle.de.|Department of Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
F Bernhard
FB
Kraus
Zentrallabor, Department of Laboratory Medicine, University Hospital Halle, Halle (Saale), Germany.
Marlies
M
Mischereit
Zentrallabor, Department of Laboratory Medicine, University Hospital Halle, Halle (Saale), Germany.
Christoph
C
Eller
Zentrallabor, Department of Laboratory Medicine, University Hospital Halle, Halle (Saale), Germany.
Beatrice
B
Ludwig-Kraus
D000328:Adult; D019963:Clinical Chemistry Tests / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D003300:Copper / Q000097:blood*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D012015:Reference Standards; D015203:Reproducibility of Results
D003300:Copper
Morbus Wilson; Roche Cobas 8000 c502; clinical chemistry; copper; method comparison; method validation