Assessing the body pool size of oxalate.
< or = 2.0 mcmol/L. Reference values have not been established for patients under 21 and greater than 81 years of age.
Because increased production and decreased excretion rates of oxalate can increase the plasma oxalate concentration, the interpretation of any given plasma value must consider the patient's clinical setting.
3 - 7 days
Patient should avoid taking vitamin C supplements for 24 hours prior to specimen collection. Collect specimen in sufficient green top tubes from a fasting patient. Place on wet ice immediately following collection. Centrifuge for 10 minutes at 2,000 rpm at 4 degrees C within 1 hour of collection and aliquot plasma into a plastic vial. Adjust the pH of the plasma specimen to a pH of 1 to 3.5 (ideal range is 2.3-2.7) with approximately 10 mcL concentrated (12N) HCl per 1 mL plasma or deliver to MLabs within 1 hour of collection. Freeze.
Fasting specimen. Place tube on wet ice immediately following collection. Deliver to laboratory or process within 1 hour of collection. Pass to Chemistry for acidification of plasma before freezing.
Test sent to Mayo Medical Laboratories.