Immunofluorescence studies can be performed on skin biopsies. Seen here is a bright green band of staining with antibody to IgG. The localization at the dermal-epidermal junction is typical, for immune complexes tend to be trapped along basement membranes. Diseases with this pattern may include systemic lupus erythematosus, discoid lupus erythematosus, and bullous pemphigoid.