Immunofluorescence is a laboratory technique used for the diagnosis of autoimmune diseases. In dermatology it is largely used for the diagnosis of autoimmune blistering diseases. Blistering is the common feature in these diseases and is believed to occur as a result of immunological attack. This attack is directed against antigenic components of desmosomes (which are responsible for epidermal cell-to-cell attachments) in the pemphigus group of diseases, or against the basement membrane zone (which is responsible for basal cell-to-matrix attachment) in the cases of subepidermal autoimmune bullous diseases, the commonest of which is bullous pemphigoid.