Figure 4: Detection of cells positive for rat or human CD68 in control animals and subjects that received CD34 + /CD34 - cell transplantation. Moderate and diffuse fluorescence signals from cells positive for rat CD68 occurs in the lesioned hemisphere of transplanted and control animals (A). A strong increase of fluorescence caused by cells positive for human CD68 cells could be detected in animals transplanted with both, CD34 + and CD34 - cells indicating a "monocyte fate" of administered cells (B). Cells positive for human CD68 could not be detected in control rats (C) or in the contralateral hemisphere. D shows the level of fluorescence according to a score point system (0=none, 1=low, 2=moderate, 3=high fluorescence activity).