Oxalate, Urine

Diagnostic Use

Oxalate was confirmed as a normal constituent of urine in 1851, but only recently has the significance of calcium oxalate crystals and its relationship to urinary tract stone formation been fully recognised.

An increased excretion of oxalate favours the formation of the very insoluble calcium oxalate in the urine, even if calcium excretion is normal. Formation of calcium oxalate in the urinary tract is considered the major cause in urinary calculi (kidney stone) formation.

An increased excretion of oxalate can be due to increased ingestion of oxalate rich foods, formation of oxalate due to metabolic defects such as hyperoxaluria (rare), and absorption of oxalate in a number of gastrointestinal disorders that produce severe fat malabsorption.

Department

Lipids/Trace Metals

Delphic Registration Code

UOX

Laboratory Handling

Registration

Register for UOX

Separating

Take aliquot for UCRN for Core Lab if not frozen. Store Trace Metals freezer.

Laboratory

Samples must be acidified and 24 hour urine volume stated on sample and request form. Please confirm pH is less than 4 before sending to CHL. Store in freezer.

Turnaround Time

1 week

Test Code

4235

Specimen Type

• Urine

Specimen Requirements

Tube/Container Type:

Preferred

• 24hr Urine Container

Acceptable

• BD Urine Tube (no additive)

Preferred Sample Volume (ml)

5

Minimum Sample Volume (ml)

2

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• BD Urine Tube (no additive)

Acceptable

• Pottle

Preferred Sample Volume (ml)

10

Minimum Sample Volume (ml)

2

Additional Specimen Information

24 hour collection into 2L bottle containing 10 mL HCL. Please confirm pH is less than 4 before sending to CHL for anaylsis.

Specimens not collected on acid are unsuitable for analysis and will not be processed.

For children a random sample collected into a urine pottle for acidification in the laboratory.

To acidfy sample: Add 50uL of HCL per 10 mL of urine, mix well and warm to 37 deg C for 5 minutes. Remix well before taking the 4 mL aliquot for analysis.

Acid urine collection bottles available from the laboratory.

Aliquot Instructions

Sample Type

• Urine

Minimum Volume (ml)

4

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Frozen

Additional Referral/Aliquot Information

Urine 4mL transport chilled. If transport is delayed store frozen.

24 hour collection into 2L bottle containing 10 mL HCL. Please confirm pH is less than 4 before sending to CHL for anaylsis.
Specimens not collected on acid are unsuitable for analysis and will not be processed.

Reference Intervals

Male 80 – 490 umol/24h

Female 40 – 340 umol/24h

Children: 140 – 420 umol/24h

Test Method

Enzymatic determination on Beckman DxC AU Chemistry analyser

Non-Funded Test Cost

$73.38 (Exclusive of GST)

Billing Code

4235

Contact Information

Enquiry Form