Donor cells preferentially found in bones. (A) Donor cell tracking after IUT by bioluminescence imaging showing no light emission in a control postnatal oim mouse that did not receive a transplant. (B) Imaging in a postnatal post-IUT oim mouse showing luminescence emitted by internal organs (ie tail [Ta], limbs [L], back spine [BS], thymus [T], heart [H], ribs [R], spleen [S], kidneys [K], brain [B], liver [Li], lungs [Lu], and skin [Sk]). (C) Quantification of photon emission on postmortem organs of in 1- and 12-week-old oim mice that received transplants. (D) Amplification plot showing change in normalized reporter dye fluorescence (ΔRn) against number of amplification cycles in samples containing from 1 to 10⁻⁷ human cDNA using human-specific primers. (E) Human specificity of primers. (F) Change in ΔRn versus the number of amplification cycles in samples containing from 1 to 10⁻⁶ human (red) and mouse (blue) cDNA using primers amplifying sequences common to human and mouse. (G) Standard curve generated from data in panel A showing samples from oim mice that received transplants (red dots). (H) Quantification of engraftment by qRT-PCR in bone versus nonbone organs at different time points in oim mice that received transplants. ***P < .001. (I) Summary of the quantification of engraftment by qRT-PCR in bone vs nonbone organs over 12 weeks postnatal.