Figure 3: (a-c) A case of bullous pemphigoid. (a) Shows a subepidermal blister, with a few eosinophils near the base (black arrow) (200×) (b) Shows PAS positive staining at the basement membrane zone (light red staining; black arrow) (200×) (c) DIF positive staining, showing linear staining of FITC conjugated antihuman Complement/C3 at the basement membrane zone (green staining; white arrow). (d-f) A case of pemphigus vulgaris. (d) Classic intraepidermal blister (black arrow) (100×) (e) PAS staining, showing some intercellular staining between keratinocytes (purple staining; black arrow) (400×) (f) DIF, showing intercellular staining of IgG FITC conjugated in a "fish scale" pattern between epidermal keratinocytes (light green staining; white arrow) (200×)