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HelpTest Code LAB405 Magnesium - Urine
Department
CHEMISTRY
Collection Requirements
Random urine.
Primary Collection Container
Yellow Urine Vacutainer (No Additive)
Transport
Urine refrigerated
Preferred Transport Temperature
Refrigerated
Processing
Adjust pH to less than 3 with 6N HCl.
Aliquot, centrifuge and refrigerate.
Stability
Ambient: 1 week
Refrigerated: 1 week
Minimum Testing Volume
0.1 mL
Reference Range
No reference ranges have been established.
Methodology
The magnesium method is a modification of the methylthymol blue (MTB) complexometric procedure described by Connerty, Lau, and Briggs. MTB forms a blue complex with magnesium. Calcium interference is minimized by forming a complex between calcium and Ba-EGTA (chelating agent). The amount of MG-MTB complex formed is proportional to the magnesium concentration and is measured using a bichromatic (600 and 510 nm) endpoint technique. Siemens Dimension Vista.
Performed
Sunday – Saturday
Reported
As completed
CPT Codes
83735
Unacceptable Conditions
Urine not acidified.