Clinics and Departments

Laboratory Services

Lab Dept:


Test Name:


General Information

Lab Order Codes:



RBC Enzyme Study; Red Cell Enzymes

CPT Codes:

82955 – G6PD
84087 – Glucose phosphate isomerase
84220 – Pyruvate kinase
82978 – Glutathione (if appropriate)
82657 – RBC Enzymes (if appropriate, done at no additional charge)

Test Includes:

Erythrocyte Enzyme Interpretation; G-6-PD, Quantitative RBC; Pyruvate Kinase, RBC; Glucose Phosphate Isomerasre; Hexokinase. This is a consultative evaluation in which the case will be evaluated at Mayo Medical Laboratories, the appropriate tests performed at an additional charge, and the results interpreted. Possible reflexed tests include: Glutathione and Reflexed RBC Enzymes.
RBC Enzymes include: adenosine deaminase, adenylate kinase, phosphofurctokinase, phophoglycerate kinase, triosephosphate isomerase, and pyrimidine 5’ nucleotidase.


Test Indications:

Useful for identifying defects of red cell enzyme metabolism and evaluating patients with hemolytic anemia.

All enzyme defects, including erythrocyte enzyme errors, are inherited; some are sex-linked and located on the X chromosome. Some family members have no hematologic abnormalities, while others have a hemolytic anemia. For a number of red blood cell enzyme defects (eg., deficiencies of hexokinase, glucose phosphate isomerase, pyruvate kinase), the sole clinical manifestation is hemolytic anemia. Glucose-6-phosphate dehydrogenase deficiency is the most common metabolic error of the red cell and presents with acute hemolytic anemia in response to oxidant stress (eg., drugs, acute infections, fava bean ingestion).

This is a consultative evaluation looking at red cell enzyme defects as the cause for early red cell destruction.

Lab Testing Sections:

Chemistry - Sendouts

Referred to:

Mayo Medical Laboratories (MML Test: 84161/EEEVP)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

2 - 10 days, test set up Monday – Friday (not reported Saturday or Sunday)

Special Instructions:

Please see Container for collection tube information.


Specimen Type:

Whole blood


Yellow top (ACD) tube or Lavender top (EDTA) tube

Draw Volume:

10 mL (Minimum: 5 mL) blood

Processed Volume:

Same as Draw Volume


Routine venipuncture

Special Processing:

Lab Staff: Do Not centrifuge. Send whole blood refrigerated in original collection container. Do Not transfer blood to other containers. Store and ship at refrigerated temperatures. Forward promptly.

Patient Preparation:


Sample Rejection:

Frozen specimens; mislabeled specimens; specimens other than EDTA or ACD whole blood; gross hemolysis


Reference Range:

Definitive results and an interpretive report will be provided. A hematopathologist expert in these disorders evaluates the case, appropriate tests are performed, and an interpretive report is issued.

Critical Values:





Kinetic Spectrophotometry


Mayo Medical Laboratories June 2012


8/25/2010: Updated units and reference ranges for Pyruvate Kinase and G6PD portions of testing.
6/7/2012: New reference range for Adenylate Kinase.

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