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Calcium, total, 24 hour urine
|Approval req'd?||Yes, if testing is requested between midnight and 8:00 AM.|
|Performed by||Parnassus Chemistry|
|In House Availability||Test available 7 days per week from 8:00 AM to midnight only.|
|Method||Ion selective electrode|
|Container type||24 hour urine collection container
Click here for Urine Preservative Requirements
|Amount to Collect||Entire 24 hour urine output.|
|Sample type||24 hour urine collection|
|Preferred volume||2 mL urine|
|Min. Volume||1 mL urine|
|Processing notes||Aliquot 1 mL and add 1 drop of 6N HCl to acidify.|
|Normal range||Usually 100-300 mg/D|
|Stability||Refrigerated 2 days|
|Turn around times||Day & evenings 4 hours. Samples received after 2000 hours will be tested the following day.|
|Additional information||To convert mg/dL to mmol/L (SI units) multiply by 0.25
Output varies with the diet. 24 hour specimens are preferable; a urine creatinine should be ordered on a spot specimen in order that any comparison of results in serial specimens can be normalized for creatinine excretion.
Gadolinium MR contrast agents including Gadodiamide (Omniscan), Gadoversetamide (Optimark), Gadopentetate Dimeglumine (Magnevist), and Gadoterdiol (Prohance), have been shown to interfere with certain colorimetric assays used in the measurement of various serum cations including iron, magnesium, and calcium. The UCSF clinical labs use electrode methods for measurement of total and ionized calcium levels which have not been reported to be subject to the gadolinium interference.
Reference:Proctor et al. Gadolinium Magnetic Resonance contrast Agents produce Analytic Interference in Multiple Serum Assays. Am J Clin Pathol. 2004;121:282-292.
|Last Updated||3/24/2013 7:38:43 PM|
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