Test Overview
Test Methodology

DNPH spot test

Test Usage

To determine urine ketoacid excretion in MSUD (maple syrup urine disease) patients. Test is also positive in patients with PKU (phenylketonuria).

Reference Range *

Interpretive report provided.

Test Limitations

Patients excreting material including low solubility drugs and x-ray contrast dye may yield a false positive result. Ketotic patients will also test positive. Positive results in previously undiagnosed patients should be confirmed by Urine Organic Acids testing. Plasma amino acid testing is required to confirm a diagnosis of MSUD. Dilute urine may show a false negative result.

Test Details
Days Set Up
Monday, Wednesday, Friday
Analytic Time

2 - 5 days

Soft Order Code
UDNPH
MiChart Code
Ketoacids, Urine by DNPH (MMGL)
Synonyms
  • UDNPH
  • Alpha-Keto Acids
  • Urine Ketoacids, DNPH
  • DNPH assay for alpha ketoacids
Laboratory
MMGL
Section
MMGL Biochemical Genetics
Specimen Requirements
Collection Instructions

Please notify MLabs Client Services Center to schedule testing prior to collecting specimen. Collect random urine specimen and freeze. Freeze each specimen immediately after collection if multiple collections are needed to reach the minimum volume. Include the patient's family history, clinical condition (asymptomatic or acute), diet, and a list of current medications with the test requisition.

Special Handling

Schedule with laboratory prior to collection.
Refrigerate and page 0603 for pick-up

Rejection Criteria
Contamination of sample with contrast media, low solubility substances, and bacteria.
Normal Volume
10 mL urine
Minimum Volume
2 mL urine
Storage Temperature
(R)-refrigerate if less than 1.5 hours transport to laboratory.
(F)-frozen if transportation requires more than 1.5 hours.
Billing
CPT Code
81005
Fee Code
23816
NY State Approved
No