A blood specimen is collected in a heparin-containing tube for calcium and magnesium determination. Upon centrifugation, the plasma appeared hemolyzed. How would this affect the magnesium value?

False hypermagnesaemia

Explanation:

Magnesium is predominantly an intracellular divalent action and it is important for optimal cellular function. It is an essential cofactor to many enzymes as well as being important for membrane function.

The body contain about 1 mol (approximately 25g) of magnesium.

Hemolyzed specimen will result in release of magnesium from intracellular to extracellular, causing elevation of the blood level of magnesium. This is a false hypermagnesaemia because it doesn't represent the real blood level.