CME ArticlePractical Direct ImmunofluorescenceKim, Randie H. MD, PhD*; Brinster, Nooshin K. MD† Author Information *Assistant Professor, The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY; and †Associate Professor, The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY. Correspondence: Nooshin K. Brinster, MD, Associate Professor of Dermatology, The Ronald O. Perelman Department of Dermatology, Dermatopathology Section, New York, NY 10016(e-mail: [email protected]). All authors, faculty, and staff in a position to control the content of this CME activity, and their spouses/life partners (if any) have disclosed that they have no financial relationships with, or financial interests in, any commercial organizations relevant to this educational activity. The American Journal of Dermatopathology 42(2):p 75-85, February 2020. | DOI: 10.1097/DAD.0000000000001516 Buy CME Test Metrics Abstract Direct immunofluorescence (DIF) remains a valuable tool that may be underused because of perceived challenges in the interpretation, limitations, and processing of DIF specimens. The aim of this review is to provide a practical guide for appropriately incorporating DIF in a variety of clinical diseases, such as autoimmune blistering disorders. In vasculitis, the role of DIF continues to evolve, particularly in the setting of IgA vasculitis. Although typically not indicated for the workup of connective tissue disease, DIF may be helpful in cases with negative serologies, nondiagnostic histologic findings, or scarring alopecia. Practical pearls for biopsy technique, specimen handling, and storage are also discussed. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.