Test Code LAB814 Calcium, Urine, 24 Hour
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Methodology
Colorimetric (NM-BAPTA)
Literature Reference:
Package insert: Calcium reagent. Roche Corporation, 12/2018.
Specimen Requirements
Specimen Type: Urine, 24 hour
Container/Tube: Plain, brown urine container
Specimen Volume: Entire collection
Collection Instructions: No additive. Refrigerate specimen during collection.
Additional Information:
1. Starting and ending times of collection are required.
2. See Urine Collection information under General Information
3. Brown urine container with green label (6N HCl) is acceptable.
Day(s) Test Set Up
Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: 2 to 4 hours after receipt in laboratory
Test Classification and CPT Coding
81050-Volume measurement for timed collection
82340-Calcium
Reference Values
25-300 mg/24 hours (diet dependent)
Literature Reference:
Rifai N, Horvath AR, Wittwer AT eds: Textbook of Clinical Chemistry and Molecular Diagnostics 6th ed: Chapter 64, p. 1422, Elsevier, St. Louis, MO 2018.
Specimen Transport Temperature
Ambient
Additional Information
For BJH Laboratory Use Only
Analyte Stability:
Collection must be kept refrigerated during the collection and before delivery to limit bacterial growth.
Laboratory Processing Instructions:
Test performed in BJH Core Lab. Mix urine well. Record volume, period, and pH on request form. Using 13x100 test tubes, prepare a 7-mL aliquot. If pH is >4, add 6 N HCl in 1 drop increments until the pH is between 2.5 and 4.0. Do not over adjust. Heat for 10 minutes at 56° C. Deliver to the automated line for centrifugation and delivery to Cobas 8000 for analysis. Completed specimen is stored refrigerated for 5 days.
Special Instructions
See Urine Collection information under General Information.
See Analyte Stability Chart under General Information for a complete list.
LOINC Code Information
Name | LOINC Code |
Calcium in 24 hour urine | 6874-2 |
Collection duration | 13362-9 |
Volume of urine | 19153-6 |