Magnesium in Human Serum with Roche c502

Detection of Magnesium in Human Serum with Roche c502

Test Name: In vitro test for the quantitative determination of magnesium in human serum and plasma on Roche/Hitachi cobas c systems.
Method Name: Colorimetric endpoint method. In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The concentration of magnesium is measured via the decrease in the xylidyl blue absorbance.
Results: Technical Range: 0.24-4.86 mg/dL
Reportable Range: 0.35-4.13 mg/dL
Reference Ranges: 0-2 years: 1.6-2.7 mg/dL
3-5 years: 1.6-2.6 mg/dL
6-8 years: 1.6-2.5 mg/dL
9-11 years: 1.6-2.4 mg/dL
12-17 years: 1.6-2.3 mg/dL
>17 years: 1.7-2.3 mg/dL
Clinical Significance: Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP dependent enzymatic reactions require Mg2+ as a cofactor in the ATP magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70% being present in free form while the other 30% is bound to proteins (especially albumin), citrates, magnesium, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65 – 1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Plasma: Li-heparin plasma

The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested.

Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.

Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.

Storage and Stability:    365 days at (-15°C) – (-20°C)
7 days at 2-8°C
7 days at 15-25°C

Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10. Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: 1 day.