Description:

Galactosylceramidase cleaves the galactose residue from the natural substrate, galactocerebroside. Deficiency of this enzyme results in Krabbe disease. This assay uses the natural substrate labeled in the galactose moiety. Upon cleavage, the radiolabeled galactose is released. In order to quantify the amount of galactose released the reaction mixture is extracted with organic solvent to remove the labeled substrate remaining leaving the free galactose in the aqueous phase. The radioactivity is determined by scintillation counting.

Specimen Requirements:

The assay is performed on white blood cells or cultured cells. For white blood cells, draw 7-10 ml in a yellow top (ACD) tube and ship to us on wet ice in an insulated container by overnight express. Sample must arrive at our location within 48 hrs. For fibroblasts, send two T25 flasks of confluent cells in an insulated container by overnight carrier.

Normal Range:

Skin Fibroblasts: 139-600 pmol/min/mg protein
White Blood Cells: 60-300 pmol/min/mg protein

Turnaround Time:

White Blood Cells: 2 weeks
Skin fibroblasts assays are growth dependent.

CPT Codes and Prices:

Skin Fibroblast Culture: 82658, 84155, 88233, 88240
White Blood Cells: 82658, 84155

Shipping Information

Forms:

>> Biochemical Requisition

Test Codes:

Skin Fibroblast Culture: 4565
White Blood Cells: 4566

Medical Genetics Laboratories
Baylor College of Medicine · Houston, TX 77030
Phone: 1-800-411-GENE · Fax: 713-798-6584
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