Laboratory: Clinical Biochemistry
Test Name:
Test Code: MIS8
Clinical Information:
It is necessary to add 100 mg of ascorbic acid immediately to 10 mL FRESH urine.  Sample must be wrapped in foil to protect from light.  For HSC samples, the Metabolic Laboratory (787-4530) must be notified that a fresh urine sample (wrapped in foil) for pterins is being sent to the laboratory so that the preservative can be added without delay.  For requests from other centres, please contact the Metabolic Laboratory to arrange for the preservative prior to collection of the urine specimen.
Collection Devices:
Specimen Required:
Urine: 10.0 mL
Pediatric Urine: 10.0 mL
Reference Values:
Tetrahydrobiopterin, Urine        52 - 86%
Neopterin:  Biopterin ratio         0.2 - 3.0
Neopterin          > 1.0 mmol/mol creatinine
Biopterin           > 0.6 mmol/mol creatinine
Within 3 Weeks
See Also:
More Information:
Add 100 mg of ascorbic acid to 10 mL fresh urine.  Wrap tube in foil.  Store and ship frozen to HSC Chemistry MS-5 for referral to London Health Sciences Centre, Biochemical Genetics Laboratory, London, ON.  Phone (519) 685-8500 ext 56495.