C-Reactive Protein Gen.3

Catalog Number: 05172373190

SYSTEM INFORMATION

CRPL3: ACN 8210

INTENDED USE

Immunoturbidimetric assay for the in vitro quantitative determination of CRP in human serum and plasma on Roche/Hitachi cobas c systems.

STORAGE AND STABILITY

CRPL3
Shelf life at 2-8 °C: See expiration date on cobas c pack label.
On-board in use and refrigerated on the analyzer: 4 weeks
On-board on the Reagent Manager: 24 hours
Diluent NaCl 9 %
Shelf life at 2-8 °C: See expiration date on cobas c pack label.
On-board in use and refrigerated on the analyzer: 4 weeks
On-board on the Reagent Manager: 24 hours

APPLICATION FOR SERUM AND PLASMA

cobas c 701/702 test definition
Assay type 2-Point End
Reaction time / Assay points 10 / 21-29
Wavelength (sub/main) 800/570 nm
Reaction direction Increase
Units mg/L (nmol/L, mg/dL)
Reagent pipetting Diluent (H2O)
R1 150 µL
R3 48 µL 24 µL
Sample volumes Sample Sample dilution
Sample Diluent (NaCl)
Normal 2 µL
Decreased 4 µL 25 µL 75 µL
Increased 4 µL

CALIBRATION

Traceability: This method has been standardized against an internal method traceable to CRM 470 (RPPHS - Reference Preparation for Proteins in Human Serum).12

Calibrators S1: H2OS2–S6: C.f.a.s. Proteins
Multiply the lot-specific C.f.a.s. Proteins calibrator values by the factors below to determine the standard concentrations for the 6-point calibration curve:
S2: 0.10000 S5: 2.0000
S3: 0.3325 S6: 4.0000
S4: 1.0000
Calibration mode 6-point spline
Calibration frequency Full calibrationafter reagent lot change as required following quality control procedures

LIMITS AND RANGES

Measuring range

0.3-350 mg/L (2.9-3333 nmol/L)

Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.

Lower limits of measurement

Limit of Blank (LoB), Limit of Detection (LoD) and Limit of Quantitation (LoQ)

The Limit of Blank and Limit of Detection were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17-A requirements.

The Limit of Blank is the 95th percentile value from n > 60 measurements of analyte-free samples over several independent series.

The Limit of Blank corresponds to the concentration below which analyte-free samples are found with a probability of 95 %. The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.

The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).

The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 30 %. It has been determined using low C-reactive protein samples.

Values below the Limit of Detection (< 0.3 mg/L) will not be flagged by the instrument.

SPECIFIC PERFORMANCE DATA

Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.

PRECISION

Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5 requirements with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained:

Repeatability Meanmg/L (nmol/L) SDmg/L (nmol/L) CV%
Precinorm Protein 9.60 (91.4) 0.06 (0.6) 0.6
Precipath Protein 49.0 (466) 0.6 (6) 1.2
CRPT Control N 3.01 (28.7) 0.05 (0.5) 1.7
Human serum A 0.840 (8.00) 0.031 (0.30) 3.7
Human serum B 2.63 (25.0) 0.04 (0.4) 1.3
Human serum C 157 (1495) 2 (19) 1.1
Human serum D 284 (2704) 3 (29) 0.9

Intermediate precision Meanmg/L (nmol/L) SDmg/L (nmol/L) CV%
Precinorm Protein 9.60 (91.4) 0.18 (1.7) 1.8
Precipath Protein 49.0 (466) 1.0 (10) 2.0
CRPT Control N 3.01 (28.7) 0.06 (0.6) 1.9
Human serum A 0.840 (8.00) 0.033 (0.31) 4.0
Human serum B 2.63 (25.0) 0.04 (0.4) 1.6
Human serum C 157 (1495) 5 (48) 3.3
Human serum D 284 (2704) 6 (57) 2.2

METHOD COMPARISON

CRP values for human serum and plasma samples obtained on a Roche/Hitachi cobas c 701 analyzer (y) were compared to those determined using the same reagent on a Roche/Hitachi cobas c 501 analyzer (x).

Sample size (n) = 92

Passing/Bablok18 Linear regression
y = 0.977x + 0.20 y = 0.975x + 0.43
t = 0.987 r = 1.000
The sample concentrations were between 0.370 and 338 mg/L (3.52 and 3218 nmol/L).