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HelpTest 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.
Reporting Name
Cytochrome b5 Reductase, BSpecimen Type
Whole Blood ACD-BSpecimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood ACD-B | Refrigerated | 18 days |
Report Available
1 to 6 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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 |
Forms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen
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
Day(s) Performed
Performed weekly
Test 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.CPT Code Information
82657
Specimen Minimum Volume
1 mL
Reference Values
≥12 months of age: 7.8-13.1 U/g Hb
Reference values have not been established for patients younger than 12 months.
Method Name
Kinetic Spectrophotometry (KS)