Cytokeratin, LMW (AE1))

Anti-cytokeratin, low molecular weight (AE1) labels most acidic keratins; therefore, it is a broadly reactive antibody staining most epithelia and their neoplasms. Members of the acidic and basic cytokeratin subfamilies are found together in pairs; each epithelium contains at least one acidic and one basic keratin so this antibody can show the distribution of keratin containing cells in epithelia. This antibody has shown great sensitivity and broad specificity for keratins under various conditions of fixation and staining. Anti-low molecular weight cytokeratin (AE1) is particularly suited to distinguish poorly differentiated carcinomas from non-epithelial neoplasms. This marker stains both normal and neoplastic cells of epithelial origin.