Diagnosis of Gaucher's disease in cultured skin fibroblasts and leucocytes.

Washing skin fibroblasts or leucocytes in 0.25 mol/l sucrose increases the activity of beta-glucosidase at acid pH. This effect is primarily due to removal of low levels of sodium chloride, which inhibit acid beta-glucosidase. A secondary factor for skin fibroblasts in the removal of residual phosphate buffer pH 7.3 used to wash the cells following trypsinization. As the beta-glucosidase activity of water-lysed leucocytes is higher at acid pH than that of a saline suspension of leucocytes, the former are better for the diagnosis of Gaucher's disease. However, more reliable results still may be obtained by assay of this enzyme in cultured skin fibroblasts.