magnesium (Mg+2) in serum
Indications
Reference interval
Principle
The Kodak Ektachem Clinical Chemistry Slide (Mg) is a dry, multilayered analytical element coated on a clear polyester support.
A 10 microliter drop of sample is deposited on the slide & evenly distributed by the spreading layer into the underlying layers. Solute molecules penetrate the scavenger layer where calcium is chelated from the sample. Magnesium (both free & protein-bound) from the sample then reacts with the formazan dye derivative in the reagent layer; the high magnesium affinity of the dye dissociates magnesium from binding proteins. The resulting magnesium-dye complex causes a shift in the dye absorption maximum from 540 nm to 630 nm. The amount of dye complex formed is proportional to the magnesium concentration present in the sample and is measured by reflection density.
Clinical significance
Magnesium is predominantly an intracellular cation, & is essential for activation of ATP that provides the basic energy for cell function. Magnesium deficiency may cause weakness, tremors, tetany & convulsions. High magnesium concentrations tend to decrease reflexes, produce somnolence & induce heart block. Patients treated for eclampsia or preeclampsia with magnesium sulfate often have serum concentrations monitored.
Increases
- also see hypermagnesemia
- renal failure
- dehydration
- tissue trauma
Decreases
- also see hypomagnesemia
- hypocalcemia
- alcoholism
- some types of malnutrition
- malabsorption
- chronic hemodialysis
- pregnancy
- hyperaldosteronism
- hyperparathyroidism
- diabetes mellitus
Specimen
No special patient preparation is necessary.
Sample Preparation: Collect the specimen by the standard venipuncture technique. Remove serum promptly from the clot & analyze as soon as possible. Lithium heparin may be used as an anticoagulant for plasma specimens. EDTA, oxalate/fluoride & citrate should not be used as anticoagulants. Refrigerate specimens if they cannot be analyzed immediately. Freeze specimens for long-term storage.
Sample requirements: Minimum- 0.5 mL serum or plasma. Optimum- 1.0 mL serum or plasma.
More general terms
More specific terms
Additional terms
Component of
- parathyroid panel
- renal function tests; renal function panel
- enteral/parenteral nutrition management panel
References
- ↑ Kodak Ektachem 700 Test Methodologies Manual, Kodak Clinical Products, Rochester, N.Y., 1990.
- ↑ Kodak Ektachem 700 Operators Manual, Kodak Clinical Products, Rochester, N.Y., 1987.
- ↑ Package Insert, Kodak Ektachem Special Calibrators, Kodak Clinical Products, Rochester, N.Y., 1985.
- ↑ Package Insert, Bio-Rad Liquichek Controls, Bio-Rad ECS Division, Anaheim, CA., 1992.
- ↑ Magnesium, Serum or Plasma Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0020039.jsp