Fig. 1.

Immunohistochemical analysis of endothelial cell replication in tissues isolated at daily intervals after induction of bone formation with cells expressing BMP-2. (A–E) On days 1, 2, 3, 4, and 5, respectively, after injection of BMP-2-producing cells, paraffin sections were prepared and stained with an antibody against Ki67, followed by a secondary antibody conjugated to Alexa fluor 488 (green) mixed with an anti–von Willibrand Factor (vWF) antibody, followed by a secondary antibody conjugated to Alexa fluor 547 (red). (F) A representative image, similar staining, taken from tissues isolated from mice injected with cells transduced with a control vector (Ad5-empty).