liquicolor (AMP Buffer, IFCC) Design Verification

Transcription

1 Design Verification (AMP Buffer, IFCC) liquicolor 1 Introduction Imprecision arity and Detection Limit arity Detection Limit Comparison of Methods Stability Stability Working Reagent Real Time Stability Recovery of Control Sera Interference Traceability... 7 QM-Element: ISO9001:2000 No /7 valid of

2 1 Introduction The performance characteristics of ALKALINE PHOSPHATASE liquicolor IFCC have been tested and documented in order to verify the clinical usefulness and compliance with the essential requirements of directive 98/79/EC. 2 Imprecision The imprecision (within-run and day-to-day) of the ALKALINE PHOSPHATASE (AMP) liquicolor method was calculated from six determinations on ten consecutive days. Predetermined pool sera of low, medium and high level were employed as sample material. Hitachi 717 Analyte concentration Intra-assay Inter-assay (U/L) SD (U/l) %CV SD (U/l) %CV arity and Detection Limit 3.1 arity The linearity of ALKALINE PHOSPHATASE liquicolor method was controlled by employing a high concentration pool serum and dilutions with phys. saline. The analysed concentrations were calculated vs. the regression line. Deviation from the regression line are expressed in absolute and relative values. As an example data measured on the Hitachi 717 are reported. High Pool Analytical Content (%) U/l U/l U/l (%) Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 2/7

3 MEASURED ANALYTE CONCENTRATION (U 2500 LINEARITY ar Regression Error Bars = ± 2SD HIGH POOL CONTENT (%) The ALKALINE PHOSPHATASE liquicolor IFCC is linear up to about 2000 U/l. 3.2 Detection Limit A 20-fold determination of a 0 calibrator (phys. saline) on a HumaStar 100 analyser revealed an absolute mean of U/l and a SD of 0.54 U/l. From the three-fold standard deviation the detection limit can therefore be calculated on the base of mean +3 SD to 2.11U/l. 4 Comparison of Methods ALKALINE PHOSPHATASE liquicolor has been compared with a commercially available alkaline phosphatase IFCC method. Control sera as well as patient samples have been employed in the comparison. The results have been evaluated by a main component analysis. The linear regression obtained could be described as follows: ALKALINE PHOSPHATASE liquicolor (Y) = * Ref. method (X) The coefficient of correlation was r = Evaluation of the method comparison by a non-parametric model according to Bablok&Passing yielded the following results: Reference (REF) Lowest value = Highest value = Arithmetic mean = Median = Standard deviation = Standard error of the mean = HUMAN AP-IFCC Lowest value = Highest value = Arithmetic mean = Median = Standard deviation = Standard error of the mean = Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 3/7

4 Y = X Intercept A : ;95% CI : to Slope B : ;95% CI : to Cusum test for linearity: No significant deviation from linearity (P>0.10) 40 0 Method Comp arison Alkaline Phosphatase IFCC REF., U/l The comparison study confirmed an excellent agreement between both methods. 5 Stability 5.1 Stability Working Reagent Recovery in Control Sera Commercially available control sera have been employed. The control sera have been reconstituted/prepared according to the manufacturer s instructions. Fivefold determinations of each control serum have been performed with ALKALINE PHOSPHATASE (AMP) liquicolor reagents. The means of the fivefold determinations have been calculated and compared with the values of fresh working reagent. Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 4/7

5 Control serum recovery Working Reagent fresh Working Reagent 5 days 25 C Working Reagent 7 days 25 C Control LOT Result Result Deviation Result Deviation serum U/l U/l (%) U/l (%) HumaTrol N # HumaTrol P # SERODOS # SERO.plus # Mean arity The linearity of ALKALINE PHOSPHATASE liquicolor was controlled according to the procedure already described in 2.1. The working reagents were stressed 5 and 7 days at 25 C. ALKALINE PHOSPHATASE working reagent 5 days 25 C ALKALINE PHOSPHATASE working reagent 7 days 25 C High Pool Analytical Analytical Content (%) U/l U/l U/l (%) U/l U/l U/l (%) The working reagent is stable for 5 days at C and for 4 weeks at 4 C. 5.2 Real Time Stability The stability of ALKALINE PHOSPHATASE liquicolor has been tested on real-time storage conditions over a period of 16, 18 and 20 months for three independent production lots (H019, exp. date: Dec ; H017, exp. date: Oct. 2003; H016.exp. date: Aug. 2003) The measurement was made on Hitachi Recovery of Control Sera Commercially available control sera have been employed. The control sera have been reconstituted/prepared according to the manufacturer s instructions. Twofold determinations of each control serum have been performed with ALKALINE PHOSPHATASE liquicolor method. The means of the twofold determinations have been calculated and compared with the values of the reference reagent. Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 5/7

6 Control serum recovery Reference Reagent Lot H019, 16 months Lot H017, 18 months Lot H016, 20 months Control LOT Result Result Deviation Result Deviation Result Deviation Serum U/l U/l (%) U/l (%) U/l (%) HumaTrol N # HumaTrol P # Serodos # Serodos plus # Serodos plus # Precinorm # Precipath # Mean arity ALKALINE PHOSPHATASE Lot H019, 16 months ALKALINE PHOSPHATASE Lot H017, 18 months High Pool Analytical Analytical Content (%) U/l U/l U/l (%) U/l U/l U/l (%) ALKALINE PHOSPHATASE Lot H016, 20 months High Pool Analytical Content (%) U/l U/l U/l (%) All results support the claimed stability of 18 months from production for the test kit. 6 Interference Interference by bilirubin, hemoglobin and lipemic sera have been studied by adding known amounts of the potentially interfering substance to a known sample. Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 6/7

7 Recoveries have been analyzed according to the method of Glick et al. (Clin.Chem. 1986, ). The results are summarised in the following table. Bilirubin mg/dl Result U/l Dev. % Hemoglobin mg/dl Result U/l Dev. % Intralipid mg/dl Result U/l Dev. % Glick This test is not significantly influenced by bilirubin up to 40 mg/dl, hemoglobin up to 250 mg/dl and lipemic sera up to 1000 mg/dl. 7 Traceability The alkaline phosphatase concentration has been verified with the reference material SRM 909 B. ALKALINE PHOSPHATASE liquicolor revealed recovery well within the reproducibility limits of the method. The method is traceable to SRM 909 B. Design Verification and Product for ALKALINE PHOSPHATASE liquicolor (AMP BUFFER; IFCC) 7/7