Detection of neo gene by PCR analysis of sorted human cells. (A) Human CD45⁺CD4⁺CD8⁺ cells were sorted from the thymic implants of 2 BM-thy-SCID-hu mice transplanted with HFBM transduced with the neo-containing MY-2 vector. The cellular DNA from the sorted human CD45⁺CD4⁺CD8⁺ thymocytes and from the mouse BM was extracted and assessed for integrated retrovirus by PCR with a neo-specific primer pair. (B) Human CD45⁺CD4⁺CD8⁻ cells were sorted from the thymic implant and PB of a BM-thy-SCID-hu mouse transplanted with HFBM transduced with the neo-containing MY-2 vector and the DNA was extracted and assessed for integrated retrovirus by PCR with a neo-specific primer pair. Southern blots using an intervening sequence probe specific for the neo primer pair-amplified product are shown.