Keratin 13 & 10

Cytokeratins (CK) are intermediate filaments of epithelial cells, both in keratinizing tissue (ie., skin) and non-keratinizing cells (ie., mesothelial cells). Although not a traditional marker for endothelial cells, cytokeratins have also been found in some microvascular endothelial cells. Atleast 20 different cytokeratins (CK) in the molecular range of 40-70 kDa and isoelectric points of 5-8.5 can be identified using two dimensional gel electrophoresis. Biochemically, most members of the CK family fall into one of two classes, type I (acidic polypeptides) and type II (basic polypeptides). At least one member of the acidic family and one member of the basic family is expressed in all epithelial cells. Monoclonal antibodies to cytokeratin proteins can be useful markers for tumor identification and classification.This antibody reacts with 53 kDa and 56.6 kDa cytokeratin (CK) proteins by Western blot. These proteins correspond to CK numbers 13 and 10, respectively, according to Moll's classification1. Using formalin-fixed, paraffin-embedded tissue sections, this antibody detects only the CK13. With frozen sections, this antibody serves as a differentation-related marker for all stratified epithelia and stains all suprabasal cell in both cornifying and non-cornifying stratified epithelia and more differentiated cells of squamous carcinomas.