Haematoxylin & Eosin stained sections of treated and control wounds. (A) Normal tissue architecture is seen in wounds taken immediately after treatment with photodynamic therapy. (B) At 24 hours, a dense cellular infiltrate appears at the wound edges inoculated with MRSA and treated with methylene blue only (L-S+). There are also smaller, focal lymphocytic aggregates infiltrating between subcutaneous adipocytes in the wound crater. (C) Following photodynamic therapy with laser light and methylene blue (L+S+), the wounds show a dense cellular infiltrate at the edges and the subcutaneous fat very similar to the control wounds.