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Test Code GALAC Galactose, Quantitative, Plasma

Reporting Name

Galactose, QN, P

Useful For

Screening for galactosemia

Testing Algorithm

This is a screening test only.


See Galactosemia Testing Algorithm in Special Instructions.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Plasma Na Heparin

Advisory Information

This test is not recommended for follow-up of positive newborn screening results. For this purpose GAL1P / Galactose-1-Phosphate (Gal-1-P), Erythrocytes and GCT / Galactosemia Reflex Test, Blood are the most appropriate tests.


This test is not appropriate for the diagnosis of galactosemia. For diagnosis, see GCT / Galactosemia Reflex, Blood.


The preferred test for monitoring dietary therapy is GAL1P / Galactose-1-Phosphate (Gal-1-P), Erythrocytes.

Specimen Required

Collection Container/Tube: Green top (sodium heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Heparin Frozen (preferred) 365 days
  Ambient  20 days
  Refrigerated  20 days

Reference Values

1-7 days: <5.4 mg/dL

8-14 days: <3.6 mg/dL

>14 days: <2.0 mg/dL

Day(s) and Time(s) Performed


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
GALP Galactose, QN, P 2308-5


Result ID Test Result Name Result LOINC Value
83638 Galactose, QN, P 2308-5

Reject Due To


Mild OK; Gross OK


Mild OK; Gross OK





Method Name

Spectrophotometric, Kinetic


Biochemical Genetics Patient Information (T602) in Special Instructions