EVALUATION OF THE KONELAB 20i CLINICAL CHEMISTRY ...

More documents

Recommendations

Info

Materials and methods The methods and reagents used in this study are summarized in Table 1. Reagents used in Konelab 20i were prepared according to the instructions of the manufacturer. They were stored in the analyzer’s refrigerated reagent compartment. Reagents for Cobas Mira were stored between analysis sections in the refrigerator at + 4 o C. Calibrators and recommended calibration intervals are given in Table 2. Materials used for between-run imprecision study are given in Table 4. For the entire evaluation, all control samples were dissolved at the same time and stored in 1 ml aliquots at –20 o C. Patient samples, minimum 81 for each analyte representing low, medium and high levels of measuring range were collected and stored at –20 o C. They were analyzed as duplicates in Konelab 20i. A single determination was performed at the same time in Cobas Mira, or on the same day in Konelab 60i or KONE Microlyte. Lithium samples were measured first in Eppendorf EFOX, then stored at –20 o C until analyzed on the same day in KONE Microlyte and Konelab 20i. Double determinations in Konelab 20i were used to calculate the within-run imprecision. In the comparative study with other instruments the first of duplicate values was used in regression analysis. The sample carry-over was studied with low and high level patient sera using Uric Acid (low level sample 105 µmol/l and high level sample 675 µmol/l) and C-Reactive Protein (low level sample 21 mg/l and high level sample 207 mg/l) tests. The reagent carry-over was studied using Lactate Dehydrogenase (240 U/l) and Alanine Aminotransferase (31 U/l) tests. Table 1. Tests, methods and reagents used in evaluation Konelab 20i Cobas Mira Test Method Method Potassium ISE, direct measurement ISE, direct measurement Sodium ISE, direct measurement ISE, direct measurement Chloride ISE, direct measurement ISE, direct measurement /Konelab 60i Lithium ISE, direct measurement ISE, direct measurement /KONE Microlyte ISE, direct measurement Flame emission / Eppendorf EFOX 5053 ALP SCE, DEA-buffer Kinetic Konelab 981359 ALT IFCC/ECCLS Kinetic Konelab 981361 C-Reactive Protein Immunoturbidimetry End-point with sample blank Konelab 981666 Cholesterol CHOD End-point with reagent blank Konelab 981368 Uric acid Uricase, Trinder (AOX) End-point with reagent blank Konelab 981391 SCE, DEA-buffer Kinetic Medix Biochemica 0054 IFCC/ECCLS Kinetic Medix Biochemica 0558 Immunoturbidimetry End-point with sample blank Orion Diagnostica 67393 and 67179 CHOD End-point with reagent blank Konelab 981368 Uricase, PAP End-point with reagent blank Roche 0736813
Table 2. Calibrators and recommended calibration intervals of the analytes Konelab 20i Cobas Mira Analyte Calibrator Cal. Interval Calibrator Cal. Interval Potassium ISE Cal 1 Every assay ISE Standard 1, 07 2568 4 Every assay Sodium Konelab 984031 ISE Standard 2, 07 2569 2 240 min interval Chloride See Konelab 20i * See Konelab 20i * Standard Solution 1, 980796 Standard Solution 2, 980797 Every assay Lithium Standard Solution 3, 980798 ** 240 min interval ** ISE Cal 2 ja 3 One month System Blank Sol. 0030 340.000 At the start and Konelab 984035 Serum Standard 0030 311.000 *** then every 10 min *** ALP Factor (molar absorptivity) - Factor (molar absorptivity) - ALT Factor (molar absorptivity) - Factor (molar absorptivity) - C-Reactive CRP Calibration Set Two weeks CRP Calibrator Set When the antisera lot Protein Konelab 981674 Orion Diagnostica 68090 changes Cholesterol Calibrator 2 Three weeks Seronorm Lipid Two weeks Konelab 980502 Sero Uric acid Calibrator 1 One month Biocal Every day Konelab 980501 Bioclin * = Konelab 60i ** = Kone Microlyte *** = Eppendorf EFOX 5053 Results Imprecision The within-run imprecision was better than 1 % in ISE measurements with exception of Lithium at low levels. For Alkaline Phosphatase, Cholesterol and Uric Acid CVs below 2 % were obtained. C-Reactive Protein gave 2.6 % for medium and high level samples and 7.9 % for low level. For Alanine Aminotransferase results CVs between 9.6 and 3.4 % were observed. Between-run imprecision (CV%) was below 3.5 % for all tests, except C-Reactive Protein. The results are presented in Tables 3 and 4. Carry-over No sample or reagent carry-over was found. Correlation The regression analysis of the results are presented in Figures 1-10. The correlations were very good. A bias of 5 to 15 % was found in the results of Lithium assays. Also a significant bias of 10 to 20 % was found for Alkaline Phosphatase results.
Page 1: EVALUATION OF THE KONELAB 20i CLINI
Page 5 and 6: Konelab 20i (mmol/l) 8,0 7,5 7,0 6,
Page 7 and 8: Konelab 20i (U/l) Konelab 20i (mg/l

EVALUATION OF THE KONELAB 20i CLINICAL CHEMISTRY ...

Create successful ePaper yourself

Delete template?

Save as template?