TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: NMHR    
N-Methylhistamine, Random, Urine

Specimen Type Describes the specimen type validated for testing

Urine

Ordering Guidance

Patients with chronic mast cell activation often have chronically elevated N-methylhistamine (NMH) levels and will sometimes have intermittent NMH elevations. In these cases, a 24-hour urine collection is preferred. See NMH24 / N-Methylhistamine, 24 Hour, Urine.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation: Patient must not be taking monoamine oxidase inhibitors (MAOIs) or aminoguanidine as these medications increase N-methylhistamine (NMH) levels.

Supplies: Aliquot Tube, 5 mL (T465)

Container/Tube: Plastic vial, 5-mL

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen within a few hours of symptom onset.

2. No preservative.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

3 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container
UrineRefrigerated (preferred)28 days
 Frozen 28 days
 Ambient 14 days