Home
HelpTest Code RPHOC Phosphorus, Random, Urine
Specimen Required
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Useful For
Evaluation of hypo- or hyperphosphatemic states
Evaluation of patients with nephrolithiasis
Reporting Name
Phosphorus, Random, USpecimen Type
UrineSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 14 days |
| Frozen | 30 days | |
| Ambient | 7 days |
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Reference Values
No established reference values
Random urine phosphorus may be interpreted in conjunction with serum phosphorus, using both values to calculate fractional excretion of chloride.
The calculation for fractional excretion (FE) of phosphorus is
FE(P)= ([P(urine) X Creat(serum)]/[P(serum) X Creat(urine)])X100
Method Description
Inorganic phosphorus reacts with ammonium molydbdate in an acidic solution to form ammonium phosphomolybdate. The ammonium phosphomolybdate is quantified in the ultraviolet range (340 nm).(Package insert: Roche Phosphorus. Roche Diagnostics; V9.0 12/2019)
Specimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84105
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| RPHOC | Phosphorus, Random, U | 2778-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| RPHOC | Phosphorus, Random, U | 2778-9 |
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 3 daysForms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.