This antibody recognizes a protein of 66 kDa-170 kDa, identified as involucrin. In Western blotting of cultured human keratinocytes, this MAb reacts with a 120 kDa protein. It stains the involucrin in a variety of sizes: 170 kDa in MCF-7 cells, a doublet of ~115 kDa and 150 kDa in gorilla and owl monkey, 66 kDa in dog, and a doublet of 105 kDa in pig. Its epitope maps between codon 421-568 of human involucrin. Involucrin is expressed in a range of stratified squamous epithelia, including the cornea, which lacks a distinct cornified layer. In normal epidermis, it is first expressed in the upper spinous layers, and in keratinocyte cultures, all cells that have left the basal layer express it. Involucrin expression is altered in pathological conditions: in psoriasis and other benign epidermal hyperplasias, involucrin expression begins closer to the basal layer than normal; expression is abnormal in squamous cell carcinomas and premalignant lesions, and is reduced in severe dysplasias of the larynx and cervix.Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.