How are specimens obtained for direct immunofluorescence?

Generally, this specialized testing would be ordered by a dermatologist, as the selection of an appropriate laboratory and proper handling of the tissue are essential to an accurate result. For most immunobullous diseases, tissue for direct immunofluorescence testing is obtained from skin next to a blister, and it is either frozen immediately in liquid nitrogen or placed in a transport medium such as Michel’s media. It should never be placed in formalin; direct immunofluorescence testing involves identifying immunoglobulins and complement deposited in the skin. These molecules may be altered by formalin.