CD34⁺ cell transduction and LAM-PCR analysis of peripheral leukocyte subsets. (A) γc expression on P1 CD34⁺ cells before and after transduction. (B) LAM-PCR analysis of the vector insertion site restriction length polymorphism present in peripheral blood leukocytes of P1. DNA samples of approximately 1 to 50 ng isolated directly from sorted peripheral blood leukocytes were analyzed at 6 months after gene therapy. Prominent bands in all lanes at the bottom of the gel are internal PCR controls. Left lane shows 100 bps DNA marker; other lanes: T, CD3⁺ cells; B, CD19⁺ cells; NK, CD16/56⁺ cells; and M, CD33⁺ myeloid cells.