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Test Code GPI Glucose Phosphate Isomerase, Erythrocytes

Reporting Name

Glucose Phosphate Isomerase, B

Useful For

A second-order test in the evaluation of individuals with chronic hemolysis

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Whole Blood ACD-B

Specimen Required


Preferred: Yellow top (ACD solution B)

Acceptable: EDTA

Specimen Volume: 6 mL

Collection Instructions: Do not transfer blood to other containers.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood ACD-B Refrigerated 20 days

Reference Values

≥12 months: 39.3-57.7 U/g Hb

Reference values have not been established for patients who are <12 months of age.

Day(s) and Time(s) Performed

Monday through Friday

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.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
GPI Glucose Phosphate Isomerase, B 44050-3


Result ID Test Result Name Result LOINC Value
GPI_ Glucose Phosphate Isomerase, B 44050-3

Reject Due To


Mild OK; Gross reject







Method Name

Kinetic Spectrophotometry (KS)