Longitudinal surveillance of clonal dynamics by LM-PCR. (A-D) LM-PCR on peripheral blood genomic DNA of 3 representative mice (#12, #13, and #14) from groups G9-14(A), G48-14(B), G9-168(C), and G48-168(D). Exponential PCR was first digested with SacI to remove internal control and then was used for nested PCR with bar-coded primers. In cases for which digest was not complete, a faint but persisting band of 280 bp was generated. M, marker; Tx, pretransplantation sample; numbers indicate the time after transplantation in months. Samples of the remaining mice are shown in supplemental Figure 5.