Calcium
Calcium
CA2
Calcium Gen.2
Order information
                                                                                                                    Analyzer(s) on which cobas c pack(s) can be used
 05061482 190           Calcium Gen.2 (300 tests)                                 System‑ID 07 7476 6               Roche/Hitachi cobas c 311, cobas c 501/502
 10759350 190           Calibrator f.a.s. (12 × 3 mL)                             Code 401
 10759350 360           Calibrator f.a.s. (12 × 3 mL, for USA)                    Code 401
 12149435 122           Precinorm U plus (10 × 3 mL)                              Code 300
 12149435 160           Precinorm U plus (10 × 3 mL, for USA)                     Code 300
 12149443 122           Precipath U plus (10 × 3 mL)                              Code 301
 12149443 160           Precipath U plus (10 × 3 mL, for USA)                     Code 301
 05117003 190           PreciControl ClinChem Multi 1 (20 × 5 mL)                 Code 391
 05947626 190           PreciControl ClinChem Multi 1 (4 × 5 mL)                  Code 391
 05947626 160           PreciControl ClinChem Multi 1 (4 × 5 mL, for USA)         Code 391
 05117216 190           PreciControl ClinChem Multi 2 (20 × 5 mL)                 Code 392
 05947774 190           PreciControl ClinChem Multi 2 (4 × 5 mL)                  Code 392
 05947774 160           PreciControl ClinChem Multi 2 (4 × 5 mL, for USA)         Code 392
 04489357 190           Diluent NaCl 9 % (50 mL)                                  System‑ID 07 6869 3
CA2
Calcium Gen.2
CA2
Calcium Gen.2
Calibration interval may be extended based on acceptable verification of            For diagnostic purposes, the results should always be assessed in
calibration by the laboratory.                                                      conjunction with the patient’s medical history, clinical examination and other
Traceability: This method has been standardized against the                         findings.
SRM 956 c Level 2 reference material.                                               ACTION REQUIRED
                                                                                    Special Wash Programming: The use of special wash steps is mandatory
Quality control                                                                     when certain test combinations are run together on Roche/Hitachi
Serum/plasma                                                                        cobas c systems. The latest version of the carry‑over evasion list can be
For quality control, use control materials as listed in the "Order information"     found with the NaOHD-SMS-SmpCln1+2-SCCS Method Sheets. For further
section.                                                                            instructions refer to the operator’s manual. cobas c 502 analyzer: All
In addition, other suitable control material can be used.                           special wash programming necessary for avoiding carry‑over is available
                                                                                    via the cobas link, manual input is required in certain cases.
Urine
                                                                                    Where required, special wash/carry‑over evasion programming must
Quantitative urine controls are recommended for routine quality control.            be implemented prior to reporting results with this test.
The control intervals and limits should be adapted to each laboratory’s             Limits and ranges
individual requirements. Values obtained should fall within the defined
limits. Each laboratory should establish corrective measures to be taken if         Measuring range
values fall outside the defined limits.                                             Serum/plasma
Follow the applicable government regulations and local guidelines for               0.20‑5.0 mmol/L (0.8‑20.1 mg/dL)
quality control.                                                                    Urine
Calculation                                                                         0.20‑7.5 mmol/L (0.8‑30.1 mg/dL)
Roche/Hitachi cobas c systems automatically calculate the analyte                   Determine urine samples having higher concentrations via the rerun
concentration of each sample.                                                       function. Dilution of samples via the rerun function is a 1:5 dilution. Results
                                                                                    from samples diluted using the rerun function are automatically multiplied
Conversion factors:                     mmol/L × 4.01 = mg/dL                       by a factor of 5.
In studies with 24‑hour urine, multiply the value obtained by the 24‑hour           Lower limits of measurement
volume in order to obtain a measurement in mg/24 h or mmol/24 h.                    Limit of Blank, Limit of Detection and Limit of Quantitation
Limitations - interference                                                          Serum/plasma and urine
Criterion: Recovery within ± 0.22 mmol/L (0.9 mg/dL) of initial value of
samples ≤ 2.2 mmol/L (8.8 mg/dL) and within ± 10 % for samples                      Serum/plasma
> 2.2 mmol/L.                                                                       Limit of Blank:                         = 0.10 mmol/L (0.4 mg/dL)
Serum/plasma
                                                                                    Limit of Detection:                     = 0.20 mmol/L (0.8 mg/dL)
Icterus:6 No significant interference up to an I index of 60 for conjugated
and unconjugated bilirubin (approximate conjugated and unconjugated                 Limit of Quantitation                   = 0.20 mmol/L (0.8 mg/dL)
bilirubin concentration: 1026 µmol/L or 60 mg/dL).                                  The Limit of Blank, Limit of Detection and Limit of Quantitation were
Hemolysis:6 No significant interference up to an H index of 1000                    determined in accordance with the CLSI (Clinical and Laboratory Standards
(approximate hemoglobin concentration: 621 µmol/L or 1000 mg/dL).                   Institute) EP17‑A2 requirements.
Lipemia (Intralipid):6 No significant interference up to an L index of 1000.        The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of
There is a poor correlation between the L index (corresponds to turbidity)          analyte‑free samples over several independent series. The Limit of Blank
and triglycerides concentration.                                                    corresponds to the concentration below which analyte‑free samples are
Magnesium: No significant interference from magnesium up to a                       found with a probability of 95 %.
concentration of 15 mmol/L (36.5 mg/dL).                                            The Limit of Detection is determined based on the Limit of Blank and the
Drugs: No interference was found at therapeutic concentrations using                standard deviation of low concentration samples.
common drug panels.7,8                                                              The Limit of Detection corresponds to the lowest analyte concentration
The interference of intravenously administered gadolinium containing MRI            which can be detected (value above the Limit of Blank with a probability of
(magnetic resonance imaging) contrast media was tested (Omniscan®,                  95 %).
Optimark®) but no interference was found at the therapeutic concentration.          The Limit of Quantitation is the lowest analyte concentration that can be
Interferences at higher concentrations were observed.                               reproducibly measured with a total error of 30 %. It has been determined
In very rare cases, gammopathy, in particular type IgM (Waldenström’s               using low concentration calcium samples.
macroglobulinemia), may cause unreliable results.9                                  Expected values10
Urine
                                                                                    Serum/plasma
Icterus: No significant interference up to a conjugated bilirubin
concentration of 1026 μmol/L or 60 mg/dL.                                           Children (0‑10 days):                   1.90‑2.60 mmol/L (7.6‑10.4 mg/dL)
Hemolysis: No significant interference up to a hemoglobin concentration of          Children (10 days‑2 years):             2.25‑2.75 mmol/L (9.0‑11.0 mg/dL)
621 μmol/L or 1000 mg/dL.
                                                                                    Children (2‑12 years):                  2.20‑2.70 mmol/L (8.8‑10.8 mg/dL)
Magnesium: No significant interference from magnesium up to a
concentration of 60 mmol/L (145.8 mg/dL).                                           Children (12‑18 years):                 2.10‑2.55 mmol/L (8.4‑10.2 mg/dL)
Urea: No significant interference from urea up to a concentration of                Adults (18‑60 years):                   2.15‑2.50 mmol/L (8.6‑10.0 mg/dL)
1600 mmol/L (9610 mg/dL).
                                                                                    Adults (60‑90 years):                   2.20‑2.55 mmol/L (8.8‑10.2 mg/dL)
Drugs: No interference was found at therapeutic concentrations using
common drug panels.8                                                                Adults ( > 90 years):                   2.05‑2.40 mmol/L (8.2‑9.6 mg/dL)
The interference of intravenously administered gadolinium containing MRI            Urine
(magnetic resonance imaging) contrast media was tested (Omniscan®,                  2.5‑7.5 mmol/24 h (100‑300 mg/24 h) with normal food intake.
Optimark®). For Omniscan® no interference was observed at the therapeutic
concentration, but there was interference at higher concentrations. For             Roche has not evaluated reference ranges in a pediatric population.
Optimark® interference was observed at therapeutic and higher                       Each laboratory should investigate the transferability of the expected values
concentrations.                                                                     to its own patient population and if necessary determine its own reference
                                                                                    ranges.
CA2
Calcium Gen.2
Specific performance data                                                      The sample concentrations were between 0.33 and 4.76 mmol/L (1.3 and
Representative performance data on the analyzers are given below.              19.1 mg/dL).
Results obtained in individual laboratories may differ.
Precision                                                                      Urine
Repeatability and intermediate precision were determined using human           Sample size (n) = 65
samples and controls in accordance with the CLSI (Clinical and Laboratory      Passing/Bablok11                     Linear regression
Standards Institute) EP5 requirements (2 aliquots per run, 2 runs per day,
21 days). The following results were obtained:                                 y = 0.989x + 0.064 mmol/L            y = 0.983x + 0.079 mmol/L
Serum/plasma                                                                   τ = 0.989                            r = 1.00
Repeatability           Mean                SD                   CV            The sample concentrations were between 0.28 and 7.47 mmol/L (1.1 and
                                                                               30.0 mg/dL).
                        mmol/L (mg/dL)      mmol/L (mg/dL)       %
                                                                               Calcium values for human serum, plasma and urine samples obtained on a
Human serum 1           0.60 (2.4)          0.01 (0.0)           2.0           Roche/Hitachi cobas c 501 analyzer using the Roche Calcium Gen.2
Human serum 2           2.55 (10.2)         0.02 (0.1)           0.8           reagent (y) were compared with those determined using the Roche Calcium
                                                                               reagent on a Roche/Hitachi MODULAR P analyzer (x).
Human serum 3           4.46 (17.9)         0.04 (0.2)           0.8
Precinorm U             2.25 (9.0)          0.02 (0.1)           0.8           Serum/plasma
Precipath U             3.51 (14.1)         0.03 (0.1)           0.8           Sample size (n) = 69
                                                                               Passing/Bablok11                     Linear regression
Intermediate            Mean                SD                   CV
                                                                               y = 1.018x - 0.027 mmol/L            y = 1.023x - 0.036 mmol/L
precision               mmol/L (mg/dL)      mmol/L (mg/dL)       %
                                                                               τ = 0.976                            r = 1.00
Human serum 1           0.60 (2.4)          0.02 (0.1)           2.5
                                                                               The sample concentrations were between 0.28 and 4.65 mmol/L (1.1 and
Human serum 2           2.55 (10.2)         0.02 (0.1)           0.9           18.6 mg/dL).
Human serum 3           4.46 (17.9)         0.04 (0.2)           0.9
                                                                               Urine
Precinorm U             2.25 (9.0)          0.02 (0.1)           0.8
                                                                               Sample size (n) = 65
Precipath U             3.51 (14.1)         0.03 (0.1)           0.9
                                                                               Passing/Bablok11                     Linear regression
Urine
                                                                               y = 1.024x + 0.018 mmol/L            y = 1.020x + 0.029 mmol/L
Repeatability           Mean                SD                   CV            τ = 0.988                            r = 1.00
                        mmol/L (mg/dL)      mmol/L (mg/dL)       %             The sample concentrations were between 0.30 and 7.25 mmol/L (1.2 and
Human urine 1           0.58 (2.3)          0.02 (0.1)           3.0           29.1 mg/dL).
Human urine 2           3.92 (15.7)         0.04 (0.2)           1.1           References
Human urine 3           5.18 (20.8)         0.05 (0.2)           0.9           1 Endres DB, Rude RK. Mineral and Bone Metabolism. In: Burtis CA,
                                                                                   Ashwood ER, Bruns ED, eds. Tietz Textbook of Clinical Chemistry and
Human urine 4           6.09 (24.4)         0.08 (0.3)           1.3               Molecular Diagnostics, 4th ed. St. Louis (MO): Saunders Elsevier
Control Level 1         1.85 (7.4)          0.02 (0.1)           1.3               2006:1891-1965.
Control Level 2         2.72 (10.9)         0.03 (0.1)           1.1           2 Heins M, Heil W, Withold W. Storage of Serum or Whole Blood
                                                                                   Samples? Effect of Time and Temperature on 22 Serum Analytes. Eur
                                                                                   J Clin Chem Clin Biochem 1995;33:231-238.
Intermediate            Mean                SD                   CV
precision                                                                      3 Wilding P, Zilva JF, Wilde CE. Transport of specimens for clinical
                        mmol/L (mg/dL)      mmol/L (mg/dL)       %                 chemistry analysis. Ann Clin Biochem 1977;14:301-306.
Human urine 1           0.58 (2.3)          0.02 (0.1)           3.1           4 Burtis CA, Ashwood ER, Bruns DE, eds. Tietz Fundamentals of Clinical
Human urine 2           3.92 (15.7)         0.05 (0.2)           1.2               Chemistry, 6th ed.St. Louis (MO): Saunders Elsevier 2008:715.
                                                                               5 Use of Anticoagulants in Diagnostic Laboratory Investigations. WHO
Human urine 3           5.18 (20.8)         0.06 (0.2)           1.1               Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002.
Human urine 4           6.09 (24.4)         0.08 (0.3)           1.3           6 Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of
Control Level 1         1.85 (7.4)          0.03 (0.1)           1.5               Interferences in Clinical Chemistry Instrumentation. Clin Chem
                                                                                   1986;32:470-475.
Control Level 2         2.72 (10.9)         0.04 (0.2)           1.3
                                                                               7 Breuer J. Report on the Symposium “Drug effects in Clinical Chemistry
Method comparison                                                                  Methods”. Eur J Clin Chem Clin Biochem 1996;34:385-386.
Calcium values for human serum, plasma and urine samples obtained on a         8 Sonntag O, Scholer A. Drug interference in clinical chemistry:
Roche/Hitachi cobas c 501 analyzer using the Roche Calcium Gen.2                   recommendation of drugs and their concentrations to be used in drug
reagent (x) were compared with those determined using the corresponding            interference studies. Ann Clin Biochem 2001;38:376-385.
reagent on a Roche/Hitachi MODULAR P analyzer (y).
                                                                               9 Bakker AJ, Mücke M. Gammopathy interference in clinical chemistry
Serum/plasma                                                                       assays: mechanisms, detection and prevention.
                                                                                   Clin Chem Lab Med 2007;45(9):1240-1243.
Sample size (n) = 69
                                                                               10 Wu AHB, ed. Tietz Clinical Guide to Laboratory Tests, 4th ed. St. Louis
Passing/Bablok11                         Linear regression                         (MO): Saunders Elsevier 2006:202-207.
y = 0.982x + 0.061 mmol/L                y = 0.982x + 0.059 mmol/L             11 Bablok W, Passing H, Bender R, et al. A general regression procedure
                                                                                   for method transformation. Application of linear regression procedures
τ = 0.979                                r = 1.00                                  for method comparison studies in clinical chemistry, Part III. J Clin
                                                                                   Chem Clin Biochem 1988 Nov;26(11):783-790.
CA2
Calcium Gen.2