Smoothelin is a constituent of the smooth muscle cell (SMC) cytoskeleton. Antibodies directed to smoothelin are useful tools to monitor SMC differentiation. Smoothelin is exclusively expressed in fully differentiated (contractile) SMCs. RNA and protein analyses revealed a broad species distribution of this protein. Cells with SMC-like characteristics, such as myofibroblasts and myoepithelial cells, as well as skeletal and cardiac muscle do not contain smoothelin. Confocal scanning laser microscopy of tissue sections, as well as transfection studies, show a filamentous organization of smoothelin that is different from that of desmin or vimentin. Smoothelin co- localizes with actin stress fibers. In Western Blots two molecular weight isoforms are detected i.e. a 50kD isoform specific for visceral SMC, and an isoform with a molecular weight of ~100kD in vascular SMC. Human smoothelin is encoded by a single copy gene which is located on chromosome 22. This target is useful to discriminate fully differentiated, contractile SMCs from proliferative SMCs. The distribution of smoothelin- positive cells indicates a correlation between smoothelin expression and smooth muscle tissue contractility. Smoothelin is also a useful tool in the evaluation of atherosclerotic lesions.

Suitable for use in Western Blot, Immunocytochemistry and Immunohistochemistry. Other applications have not been tested.

Immunohistochemistry: Frozen and paraffin embedded tissue. For use on paraffin embedded sections, the sections should be pre-treated with 10mM citrate buffer (pH 6.0) and heated for 3-5 minutes. Optimal dilutions to be determined by the researcher.

Store product at 4°C in the dark. DO NOT FREEZE! Stable at 4°C for 12 months after receipt as an undiluted liquid. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Caution: MaxLight™490 conjugates are sensitive to light. For maximum recovery of product, centrifuge the original vial prior to removing the cap.

Note: Applications are based on unconjugated antibody.

Cytoskeletal extract of chicken gizzard

Supplied as a liquid in PBS, pH 7.2. No preservative added. Labeled with MaxLight™490.

Purified from culture supernatant

Recognizes chicken smoothelin, a cytoskeletal protein exclusively found in smooth muscle cells at 59kD and 100kD |Species Crossreactivity: human, canine, feline, porcine and monkey. Not with hamster, rat or mouse.