Figure 6.

Demonstration of human CD45⁺ cells in the marrow spaces of secondary transplants by immunohistochemistry. (A): Spines with intact marrow spaces were decalcified by EDTA immersion, paraffin embedded, and sliced into 8-µm sections for analysis by immunohistochemistry. Staining with an anti-human CD45 monoclonal antibody demonstrated the engraftment of human cells in hematopoietic spaces. Black arrows point to examples of positively stained cells. (B): Isotype (negative) control demonstrates the absence of background and specificity of the anti-CD45 antibody.