Phosphate (PO4)
Chemical Pathology
Notes
Phosphate can be measured in urine but is generally not helpful. One exception is when an assessment of the tubular reabsorption of phosphate (TRP) is required. This requires simultaneous blood and urine samples with the urine collected as a spot sample.
Sample requirements
For adults, blood taken into a 5 mL gold top gel tube (or rust top for the Acute Unit)
For children, blood taken into a 3.5 mL rust top tube
For neonates, blood taken into a 0.8 mL minicollect lithium heparin tube. Please list the tests of particular interest so that some priority can be given to analysis if plasma volumes are small.
For TRP, a minimum of 5mL urine into a white top 25 mL Universal container
Storage/transport
Do not store. Send blood and urine samples at ambient temperature to the laboratory the same day.
Required information
Relevant clinical details.
Turnaround times
The assays are run throughout the day and night.
The in-lab turnaround time is normally less than 24 hours.
The test can be ordered as an urgent request.
Reference ranges
| Age | Reference range (mmol/L) |
|---|---|
| < 5 days | 1.50 – 2.60 |
| 5 days – 3 years | 1.20 – 2.10 |
| 3 years – 10 years | 1.20 – 1.80 |
| 10 years – 15 years | 1.10 – 1.75 |
| > 15 years | 0.80 – 1.50 |
Further information
To learn more about phosphate visit Lab Tests Online or access the Phosphate monograph of the Association for Clinical Biochemistry and Laboratory Medicine
Page last updated: 14/01/2023