Immunofluorescence analysis of cells within tonsil grafts. Immunofluorescence was used to assess coexpression of multiple markers by the cells within tonsil grafts recovered at 4 weeks after surgery. (A) Three-color staining to detect expression of human CD3 (green), Ki-67 (blue), and mouse (m) CD11b (red). Enlarged view of cells expressing both Ki-67 and CD3 indicated by arrows (far right panel). (B) Three-color staining to detect expression of human CD138 (green), Ki-67 (blue), and human CD27 (red). Enlarged view of cells expressing both Ki-67 and CD138 indicated by arrow (far right panel). (C) Four-color staining (with only 3 of these shown in a given panel) to detect expression of human CD3 (red), human CD138 (green), Ki-67 (blue) in the left 2 panels and human CD138 (green), Ki-67 (red), and mCD11b (blue) in the right 2 panels. Right panel of each pair shows enlarged image. Scale bar represents 50 μm. Staining is representative of 5 tonsil grafts from each of 3 different grafting experiments.