Osteocalcin (OCN)

Catalog Number: 12149133160

INTENDED USE

Immunoassay for the in vitro quantitative determination of N-MID osteocalcin in human serum and plasma. The determination of osteocalcin, an indication of human bone formation and osteoblastic activity, may be useful as an aid in the management of postmenopausal osteoporosis.

The electrochemiluminescence immunoassay “ECLIA” is intended for use on Elecsys and cobas e immunoassay analyzers.

STORAGE AND STABILITY

Stability:
unopened at 2-8 °C up to the stated expiration date
after opening at 2-8 °C 12 weeks
on the analyzers 8 weeks

Store at 2-8 °C.

Do not freeze.

Store the Elecsys reagent kit upright in order to ensure complete availability of the microparticles during automatic mixing prior to use.

CALIBRATION

Traceability: This method has been standardized against in-house reference standards: osteocalcin in analyte-free human serum matrix.

Every Elecsys reagent set has a barcoded label containing specific information for calibration of the particular reagent lot. The predefined master curve is adapted to the analyzer using the relevant CalSet.

Calibration frequency: Calibration must be performed once per reagent lot using fresh reagent (i.e. not more than 24 hours since the reagent kit was registered on the analyzer). Renewed calibration is recommended as follows:

LIMITS AND RANGES

Measuring range

0.500-300 ng/mL (defined by the lower detection limit and the maximum of the master curve). Values below the lower detection limit are reported as < 0.500 ng/mL. Values above the measuring range are reported as > 300 ng/mL (or up to 1500 ng/mL for 5-fold diluted samples).

Lower limits of measurement

Lower detection limit of the test

Lower detection limit: < 0.500 ng/mL.

The lower detection limit represents the lowest measurable analyte level that can be distinguished from zero. It is calculated as the value lying two standard deviations above that of the lowest standard (master calibrator, standard 1 + 2 SD, repeatability study, n = 21).

SPECIFIC PERFORMANCE DATA

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

PRECISION

Precision was determined using Elecsys reagents, pooled human sera and controls in a protocol (EP5-A2) of the CLSI (Clinical and Laboratory Standards Institute): 2 runs per day in duplication each for 21 days (n = 84). The following results were obtained:

Elecsys 2010 and cobas e 411 analyzers
Repeatability Intermediate precision
Sample Meanng/mL SDng/mL CV% SDng/mL CV%
Human serum 1 6.01 0.085 1.4 0.186 3.1
Human serum 2 12.2 0.135 1.1 0.373 3.1
Human serum 3 35.6 0.601 1.7 1.06 3.0
Human serum 4 169 3.12 1.8 5.56 3.3
Human serum 5 8.11 0.091 1.1 0.159 2.0
PreciControl Varia 1 19.3 0.164 0.8 0.267 1.4
PreciControl Varia 2 93.2 1.01 1.1 1.65 1.8

MODULAR ANALYTICS E170, cobas e 601 and cobas e 602 analyzers
Repeatability Intermediate precision
Sample Meanng/mL SDng/mL CV% SDng/mL CV%
Human serum 1 6.11 0.056 0.9 0.120 2.0
Human serum 2 12.0 0.126 1.1 0.240 2.0
Human serum 3 34.5 0.361 1.0 0.677 2.0
Human serum 4 160 2.03 1.3 3.65 2.3
Human serum 5 7.49 0.066 0.9 0.107 1.4
PreciControl Varia 1 17.9 0.166 0.9 0.207 1.2
PreciControl Varia 2 85.9 0.755 0.9 1.12 1.3

METHOD COMPARISON

A comparison of the Elecsys N-MID Osteocalcin assay (y) with a commercially available N-MID osteocalcin test (x) using clinical samples gave the following correlations (ng/mL):

Number of samples measured: 48

The sample concentrations were between approximately 2.58 and 49.8 ng/mL.

Passing/Bablok12
y = 1.31x + 2.0
r = 0.966
md(68) = 0.816

ANALYTICAL SPECIFICITY

For the monoclonal antibodies used, the following cross-reactivities were found:

No cross-reactivity detectable for b-CrossLaps, parathyroid hormone, and bone-specific alkaline phosphatase.