Recently, a monoclonal antibody, 19-DEJ-1, has been described with binding specificity for an epitope present within the mid-lamina lucida of the dermoepidermal junction directly underneath hemidesmosomes, suggesting recognition of a portion of the anchoring filaments. In an initial survey of specimens from patients with inherited epidermolysis bullosa (EB), it was noted that 9 of 9 specimens of Herlitz junctional EB and approximately 50% of specimens of recessive dystrophic EB lacked staining of the dermoepidermal junction with this antibody. To better define the sensitivity of binding by 19-DEJ-1 in junctional EB skin, 40 consecutive specimens representing the three major subtypes (Herlitz, 14; non-Herlitz, 15; and indeterminate, 11) were examined. No staining was noted along the dermoepidermal junction in any specimen, regardless of junctional EB subtype. Considering the recently discovered variability of binding by GB3 monoclonal antibody in some junctional EB subtypes, based on the present data it appears that the 19-DEJ-1 monoclonal antibody is the only immunohistochemical probe that can be used reliably for diagnosis of all major forms of junctional EB. Furthermore, these data suggest the possible utility of this particular antibody as a probe for identification, at the molecular level, of a basement membrane defect shared among all major forms of junctional EB.