Figure 4.

Immunofluorescence staining for MLC2a and MLC2v 30 days after cell transplantation demonstrating the maturation of hTNNI3-positive cells in vivo. (A) Panoramic immunofluorescence staining for TNNT2 (human and rat cardiomyocytes) and hTNNI3 (human-specific cardiomyocytes). (B–D) Images showing the area depicted by the white rectangle in A (hTNNI3-positive cardiomyocytes) in higher magnification with a single channel for each marker. (B) TNNT2 (green, rat and human cells), (C) human TNNI3 (orange, note the absence of rat tissue compared with (B,D) nuclei (blue). (E) Serial slices were stained with TNNT2 (green), MLC2a (red), and nuclei (blue). Note that the graft in C is the same as that used in E. (F) MLC2a (red) showing scant expression on the graft. (G) Merged image for TNNT2 (green), MLC2v (red), and nuclei (blue). (H) MLC2v showing extensive labeling, compared with MLC2a in (F). Scale bars: 100 µm.