Test ID METR1 Cytochrome b5 Reductase Enzyme Activity, Blood
Necessary Information
Specimen Required
Collection Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Useful For
Evaluation of patients with cyanosis
Confirming cases of suspected cytochrome b5 reductase (methemoglobin reductase) deficiency
Functional studies in families with cytochrome b5 reductase deficiency
Method Name
Kinetic Spectrophotometry (KS)
Reporting Name
Cytochrome b5 Reductase, BSpecimen Type
Whole Blood ACD-BSpecimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood ACD-B | Refrigerated | 18 days |
Reference Values
≥12 months of age: 7.8-13.1 U/g Hb
Reference values have not been established for patients who are younger than 12 months.
Performing Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
METR1 | Cytochrome b5 Reductase, B | 32703-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
METRB | Cytochrome b5 Reductase, B | 32703-1 |
NY State Approved
YesDay(s) Performed
Performed weekly
Report Available
1 to 6 daysCPT Code Information
82657
Forms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen