Summary of normalized median fluorescence (MF ) values of monocytes (CD14⁺) isolated from Gaucher patients or normal controls. PBMC obtained in four separate experiments from six unrelated patients and seven controls were collected, processed, and analyzed by FACS as described in Fig 4. CBE inhibition was carried out in parallel to determine the GC specific contribution for each sample. The normalized median fluorescein fluorescence values of monocytes are shown for all samples. Three of the control samples (•) were collected from a single individual on 3 different days. To compare analyses conducted on separate days. The CBE correction was conducted, and the mean of the resulting “GC specific” value of the control samples was determined. The activities of all samples were normalized by dividing by this value. The standard deviation of normalized control MF values was ±10%. The mean corrected fluorescein fluorescence of Gaucher patient samples was 19% (SD ± 7% of that determined for control samples (P < .002). Statistical analysis was conducted with JMP software using the Mann-Whitney U test.