(Prod. No. 10600/ 10650)

Background

In eukaryotic cells, the cytoskeleton is composed of three different types of morphologically distinct filamentous structures:

• microfilaments,
• intermediate filaments (IF),
• microtubules.

The epithelial keratins (IF types I and II, also called cytokeratins) are conserved phylogenetically and are closely related, biochemically and imunologically. Keratins 1-8 constitute the type II group (53-68 kDa, neutral to basic protein components), while keratins 9-20 constitute the type I group (40-56 kDa, acidic proteins).

Upon release from dying cells, keratins provide useful markers for epithelial malignancies, distinctly reflecting ongoing cellular turnover. Certain keratins, the most prominent example being keratin 18, are substrates for lethal caspase activation and the subsequent release of defined protein fragments occurs during apoptotic cell death.

The clinical value of determining different soluble keratin protein fragments in blood samples (i.e. using the M30 Apoptosense® ELISA or M65® ELISA) lies in the rapid and non-invasive assessment of drug efficacy or response to therapy in epithelial cell carcinomas.

Figure
The M5 Keratin 18 antibody is a versatile tool for easy and reliable detection of human epithelial cells and tissues by a broad range of applications. These include Western blot, immunocytochemistry, immunoprecipitation, flow cytometry and immunohistochemistry of formalin fixed and paraffin embedded (FFPE) tissue sections.
Image shows staining of epithelial cells within a FFPE prostate tissue section using M5 Keratin 18 from PEVIVA. Secondary detection with anti mouse IgG biotin, streptavidin POD and DAB as substrate.

The antibody M5 Keratin 18 recognizes a conventional internal epitope present on uncleaved K18 in healthy or released from necrotic cells as well as the caspase-cleaved K18 fragment released selectively from apoptotic epithelial cells or tissues.
Therefore, M5 Keratin 18 antibody is a highly sensitive tool for the specific identification and quantification of cells of simple epithelial origin within a tissue or mixed cell population or to confirm K18 expression in a particular cell line model.

Figure
Detection of Keratin 18 (K18) in frozen section from human prostate tissue showing confined staining for K18 in epithelial cells using M6 Keratin (right panel) and nuclear counterstain with DAPI (left panel). Secondary detection with anti mouse IgG ALEXA 488.

The antibody M6 Keratin 18 recognizes a conventional internal epitope present on uncleaved K18 in healthy or released from necrotic cells as well as the caspase-cleaved K18 fragment released selectively from apoptotic epithelial cells or tissues.

Therefore, M6 Keratin 18 antibody is a highly sensitive tool for the specific identification and quantification of cells of simple epithelial origin within a tissue or mixed cell population or to confirm K18 expression in a particular cell line model.