Application note cobas c501 v08-mars 201

For in vitro diagnostic use only General Information
2-8ºC. Below -20ºC for at least 10 years (submitted Clinical Intended Use
Chemistry November 2010). Mix samples well before The Gentian Cystatin C Immunoassay is an in vitro diagnostic analysing. The samples may be shipped without special test for quantitative determination of cystatin C in human serum cooling, but must then be analysed within 14 days after and plasma. The measurement of cystatin C is used in the diagnosis and treatment of renal disease. Measuring range
The Gentian Cystatin C Assay Buffer is the Reaction Buffer R1. The buffer is ready for use. The overall measuring range of cystatin C concentration for Gentian Cystatin C Immunoassay on the Cobas c5011 analyzer Immunoparticles (R3)
The Gentian Cystatin C Immunoparticles are ready for use. Reference intervals
Calibrator
Gentian followed the CLSI Guideline, C28-A2 to determine the The calibrator is ready to use and a dilution series for transferability of the reference interval. The reference interval calibration curve establishment is prepared automatically by was determined from a population of ostensibly healthy subjects with no history of renal disease. A total of 136 samples obtained from 58 males and 78 females ranging in All reagents are stable until the expiry date given on the
age from 20 to 80 years were tested. The reference interval labels when stored at 2-8ºC.
was calculated non-parametrically and was determined to be 0.51-1.05 mg/L. This represents the central 95 % of the Calibrator Standardisation
population. It is recommended that every laboratory should Gentian Cystatin C Calibrator is standardised against the determine a local reference interval since values may vary international calibrator standard ERM-DA471/IFCC. depending on the population tested. In a separate study Calibration Stability
involving 850 healthy children (46% boys, 54 % girls) in the age The established calibration curve is stable for 4 weeks on from 5 to 15 years, the reference range 0.51 - 1.05 mg/L was Cobas c5011. When reagent lots are changed or measured confirmed in all ages down to 5 years of age [5]. control values are outside the assigned range given in the Analytical Value Sheet, a recalibration is recommended. GFR prediction calculation
Several cystatin C based prediction equations for calculation of
Onboard Stability
GFR for adults and children have been published. It should In appropriate bottles, Gentian Cystatin C Immunoparticles and noted that these formulas were evaluated with different Assay Buffer are stable for at least 9 weeks when stored immunoassay PENIA or particle enhanced turbidimetric immunoassay PETIA) and may reveal inaccurate GFR results if Assay Procedure
an inappropriate combination of formula and assay is used. For Application Notes/Assay Installation
calculation of GFR from cystatin C values measured with the An Instrument Parameter list is available in the section “Instrument Settings” below. The Application Note is also recommended using mg/L as the unit factor [4]: The equation is available at www.gentian.no. Instrument set up, maintenance, operation and precautions must be handled in accordance with Reagents Preparation
Reagent is supplied ready to use. Use a suitable pipette to Materials Provided by Gentian AS
transfer the calculated volumes (see the instruments manual) of Reagent 1 and Reagent 3 into the appropriate compartments Gentian Cystatin C Kit (REF1101):
of the Open Channel Reagent Cassette (cobas c pack Gentian Cystatin C Immunoparticles, bottle of 10 mL, (R2) MULTI1). Mix well before transfer. Use care to avoid Gentian Cystatin C Assay Buffer, bottle of 58 mL, (R1) contamination. Reagents should be stored capped at 2-8°C when not in use. Gentian Cystatin C Calibrator: vial of 1 mL, REF1012
Gentian Cystatin C Calibrator Kit: 6 levels, vials of 1 mL,
Contact your distributor or Gentian to get information on how to maximise the number of tests per reagent kit. The information Gentian Cystatin C Control Kit: 2 vials of 1 mL, REF1019
Gentian Cystatin C Control Kit: 2 vials of 5 mL, REF1026
All materials are ready to use.

Establishment of the Calibration Curve
Use Gentian Cystatin C Calibrator, REF1012 to establish a Specimen
6-point standard curve as defined in the instrument manuals. Required sample material is human serum, heparinized plasma Calibrator values are lot dependent and a new calibration must and EDTA plasma. It is recommended to analyse the samples be performed whenever a new calibration lot is used. The as fresh as possible. Sample stability testing showed that calibrator’s assigned values are given on the analytical value cystatin C in serum and plasma samples are stable for 14 days at room temperature (8-25ºC) and for 21 days if stored at 1A registered trademark of Roche Diagnostics Application Note for Gentian Cystatin C Immunoassay on Cobas1 c501, Roche QC Controls
There is no interference detected with the drugs tested on The controls low and high must be assayed each day before any samples are assayed in order to validate the calibration interference study was designed in accordance with the curve. The controls have an assigned value range that must be protocol EP7-A from CLSI [2]. There is no RF interference met before measuring samples. The assigned values are given present in the Gentian Cystatin C Immunoassay because the in the Analytical Value sheet included with the Gentian Cystatin antibodies are made from avian (chicken) [3]. C Control Kit (REF1019 or REF1026). If the control values are not valid, repeat the control measurements. If the calibration cannot be performed without error, or valid control values Shipping Damage
cannot be reproduced, contact the manufacturer for support. Please notify your distributor if this product is received damaged. Measuring Patient Samples
When a valid calibration has been performed and the control values are within the valid range, serum or plasma samples may be measured. Check that minimum volume of sample is Symbols Key
present and assay the samples according to the instructions given in the Instrument Manuals. Results
The results are calculated automatically by the Cobas c5011
instrument. The results are presented in mg/L. Performance Characteristics
All results refer to the validation of Gentian Cystatin C Immunoassay on Cobas c5011. Detection Limit
Limit of Quantification is defined as: The lowest actual amount of an analyte that can be reliably detected and at which the total error meets the requirements for accuracy. Gentian Cystatin C Immunoassay has a Limit of Quantitation of Precision
The Gentian Cystatin C Immunoassay was used in a 5-day precision study designed in accordance with CLSI protocol References
EP5-A. 5 human serum pools were measured on the Cobas [1] Sonntag O, Scholer A: Ann Clin BIochem 2001; 38:376-85. [2] CLSI; Document EP7-A; Interference Testing in Clinical Chem.; Mean value
Within-Run
Serum pool
[3] Larsson A et al: Poultry Science 1993;72:1807-1812 [4] Flodin M et al: Scand J Clin Lab Invest 2007;67:560-567 [5] Nitsch D. et al: Foetal, developmental and parental influences on Childhood cystatin C in Childhood. Submitted for publication. Linearity
Manufacturer:
Gentian Cystatin C Immunoassay on Cobas c5011 is linear in Gentian AS, PO BOX 733, N-1509 Moss, Norway the range of 0.41-7.98 mg/L. Concentrations outside this range have not been tested. Interference
EC REP Authorized European Representative in EU:
No interference is detected with Triglycerides (12.7 mmol/L) Gentian AS, PO BOX 733, N-1509 Moss, Norway Haemoglobin (8.0 g/L), Intralipid (14 g/L) or Bilirubin (600 mg/L) on Cobas c5011.
1A registered trademark of Roche Diagnostics Application Note for Gentian Cystatin C Immunoassay on Cobas1 c501, Roche For in vitro diagnostic use only Assay/Time/Point
2 point end
Wavelength (2nd /primary)
S.vol (Normal)
S.vol (Decrease)
S.vol (Increase)
Reagent (R1) T1
Reagent (R2) T2
Reagent (R3) T3
Reagent (R4) T4
Abs. Limit
Increase
Prozone Limit
Cell Detergent
Detergent 1
1A registered trademark of Roche Diagnostics Application Note for Gentian Cystatin C Immunoassay on Cobas1 c501, Roche CALIBRATION

Calibration Type
Span Point

Auto calibration:


Diluent:
Saline (from instrument for auto-dilution of calibrator)
1A registered trademark of Roche Diagnostics Application Note for Gentian Cystatin C Immunoassay on Cobas1 c501, Roche Application Code:
Expected Values:
Standard:

CV: assigned Calibrator Value, see analytical value sheet enclosed with the calibrator

* User defined
** Calibrator Position chosen by user
1A registered trademark of Roche Diagnostics Application Note for Gentian Cystatin C Immunoassay on Cobas1 c501, Roche

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