Comparison of donor chimerism by DNA versus flow cytometry analysis. Peripheral blood leukocytes were analyzed for CLAD dog D102 (A), CLAD dog D106 (B), and CLAD dog D114 (C). Flow cytometry with an anti-CD18 monoclonal antibody was used to detect the percentage of CD18⁺ leukocytes (solid lines, ▪) in the peripheral blood of the CLAD dogs. Chimerism in the peripheral blood leukocytes was also determined by PCR amplification of donor microsatellite repeats at the selected time points (dashed lines, ▴). DNA chimerism data were subjected to a correction value on the basis of peak height and area differences between donor and recipient peaks (described in “Methods and materials”).