Ordering Guidance

Random urine collections are preferred for patients with episodic symptoms, for example in the context of allergic reactions brought on by specific environmental factors. For random urine collections, order MCMRU / Mast Cell Mediators, Random, Urine.

Specimen Required

Patient Preparation:

1. Patient must not be taking monoamine oxidase inhibitors (MAOI) or aminoguanidine, as these medications increase N-methylhistamine (NMH) levels.

2. Patients taking aspirin or nonsteroidal anti-inflammatory drugs (NSAID) may have decreased concentrations of prostaglandin F2 alpha (23BP). If possible, the patient should discontinue use for 2 weeks or 72 hours, respectively, before specimen collection.

Supplies: Urine Container, 60 mL (T313)

Collection Container/Tube: Plastic urine container

Submission Container/Tube: Plastic, 60-mL urine bottle

Specimen Volume: 20 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. No preservative.

3. Aliquot urine into plastic tube and send to lab.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.