A biochemical assay for GUSB activity revealed a similar widespread distribution of enzyme in the tissues of NOD/SCID/MPSVII mice at both 6 and 12 weeks following transplantation of human CD34⁺ cells.

The tissues of NOD/SCID/MPSVII mice that received transplants of human C34⁺ cells derived from cord blood were analyzed 6 (A) or 12 (B) weeks later with the GUSB-specific biochemical assay. The GUSB-specific activities (U = nmol substrate cleaved/hour/mg protein) for the tissues of each mouse were divided by the percentage of human CD45⁺ cells in the bone marrow of the respective mouse. The adjusted values from 4 mice at each time point were averaged and are shown with the standard error. Data are presented for the spleen, mesenteric lymph nodes (LN), thymus, peripheral blood leukocytes (PBL), liver, lung, kidney, heart, and brain. The bone marrow of these mice had an average of 6.5 ± 2.3 U/percentage of CD45⁺ and 7.3 ± 2.9 U/percentage of CD45⁺ at 6 and 12 weeks following transplantation, respectively.