Test ID METR Methemoglobin Reductase, Blood
Useful For
Confirming cases of suspected methemoglobin reductase (cytochrome b5 reductase) deficiency
Functional studies in families with methemoglobin reductase (cytochrome b5 reductase) deficiency
Method Name
Kinetic Spectrophotometry (KS)
Reporting Name
Methemoglobin Reductase, BSpecimen Type
Whole Blood ACD-BSpecimen Required
Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Do not transfer blood to other containers.
Additional Information: Patient's age is required.
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood ACD-B | Refrigerated | 22 days |
Reference Values
≥12 months: 6.6-13.3 U/g Hb
Reference values have not been established for patients who are <12 months of age.
Day(s) and Time(s) Performed
Tuesday, Thursday
Performing Laboratory

CPT Code Information
82657
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
METR | Methemoglobin Reductase, B | 32703-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
9322 | Methemoglobin Reductase, B | 32703-1 |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.NY State Approved
YesForms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen.