SUMMARY, EXPLANATION AND LIMITATIONS:
Cytokeratins (CK) are intermediate filaments that constitute the cytoskeletal structure of virtually all epithelial but also of some non-epithelial cells. According to R. Moll they can be divided into Type I (acidic cytokeratins, CK9 to 20) and Type II (basic cytokeratins, CK1 to 8). The antibody of clone D5/16B4 detects basic high-molecular CK5 (58 kDa) and CK6 (56 kDa). Additionally, it reacts weakly with CK4 in Western blots. CK5 is expressed in basal, intermediate and superficial layers of stratified epithelia, transitional and complex epithelium and mesothelium. In complex epithelia CK5 is detectable in some basal cells. Only a few simple epithelia and non-epithelial cells express CK5. CK6 is expressed by proliferating squamous epithelium and is often paired with CK16 (48 kDa). An important application of CK5/6-antibody is discrimination of poorly differentiated squamous cell carcinomas (mostly positive) from adenocarcinomas (mostly negative) and of mesotheliomas (positive) from lung carcinomas (negative). It has been reported that strong CK5/6 positivity in ductal hyperplasia and negative staining of most cases of atypical ductal hyperplasia may assist in the differential diagnosis of atypical proliferation of the breast. CK5/6 antibodies are, like p63 or CK HMW (34βE12), also used for staining of myoepithelial cells for the detection of benign glands of the prostate.
Immunogen: Purified cytokeratin 5.
Staining pattern: Cytoplasmic.
Positive control: Tissue sample from mesotheliomas, squamous cell carcinomas or prostate.
This antibody is designed for the specific localization of human Cytokeratin 5/6 using IHC techniques in formalin-fixed, paraffin-embedded tissue sections.