Magnesium Flashcards
MAGNESIUM
_____most abundant cation
Fourth
MAGNESIUM
____most abundant intracellular ion
Second
Most abundant cation
- Sodium
- Potassium
- Calcium
- Magnesium
Most abundant intracellular ion
- Potassium
- Magnesium
- Phosphate
FUNCTIONS
• Essential cofactor (>300 enzymes)
• Transcellular ion transport
• Neuromuscular transmission
• Synthesis of carbohydrates, proteins, lipids, and nucleic acid
• Release of and response to certain hormones
SPECIMEN CONSIDERATIONS
Serum (Non-hemolyzed)
Lithium Heparin Plasma
24-hour urine
Anticoagulants that will bind
with magnesium
Oxalate
EDTA
citrate
Why 24-hour urine?
Eliminates the interference caused by diurnal variation
24 hr urine
Must be acidified with___ to avoid___
HCl
precipitation
METHODS
• Colorimetric Methods
• Atomic Absorption Spectrophotometry
Colorimetric Methods
• Calmagite Method
• Formazen Dye Method
• Methylthymol Blue Method
Colorimetric Methods
• Mg+ binds with calmagite to form a reddish-violet complex that may be read at 532 nm
Calmagite Method
Colorimetric Methods
• Calmagite Method
• Mg+ binds with_____ to form a_____(color) that may be read at____
calmagite
reddish-violet complex
532 nm
Colorimetric Methods
• Mg+ binds with the dye to form colored complex that may be read at 660 nm
Formazan Dye Method
Colorimetric Methods
• Formazan Dye Method
• Mg+ binds with the___ to form____(color) that may be read at____
Formazan dye
colored complex
660 nm
Colorimetric Methods
• Mg binds with the chromogen to form a colored complex
Methylthymol Blue
Colorimetric Methods
• Methylthymol Blue
• Mg binds with the______ to form a _____ (color)
chromogen - Methylthymol Blue
colored complex - Blue
• Reference Method
Atomic Absorption Spectrophotometry
Approximately 53% of Mg2+ in the body is found in____, 46% in_____, and less than 1% is present in_____.
bone
muscle and other organs and soft tissue
serum and RBCs
Mg2+ concentration inside erythrocytes is____ times greater than that in the ECF, ____ should be avoided and the serum should be separated from the cells as soon as possible.
10
Hemolysis
Magnesium must be analyzed…
As soon as possible