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Test ID GPI1 Glucose Phosphate Isomerase Enzyme Activity, Blood

Specimen Required


Preferred: Yellow top (ACD solution B)

Acceptable: Lavender top (EDTA)

Specimen Volume: 6 mL

Collection Instructions: Send in original tube. Do not transfer blood to other containers.

Useful For

The evaluation of individuals with Coombs-negative chronic hemolysis

Method Name

Kinetic Spectrophotometry (KS)

Reporting Name

Glucose Phosphate Isomerase, B

Specimen Type

Whole Blood ACD-B

Specimen Minimum Volume

1 mL

Specimen Stability Information

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

Reference Values

≥12 months: 40.0-58.0 U/g Hb

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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 US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
GPI1 Glucose Phosphate Isomerase, B 44050-3


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

Day(s) Performed

Tuesday, Thursday

Report Available

1 to 6 days


If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.