Vimentin is an intermediate filament with a molecular weight of ~58kD, and an average diameter of 10 nm. Within the same species, the central domain of the filament is 30% homologous to cytokeratin, desmin, neurofilaments, and glial fibrillary acidic protein. Vimentin is ubiquitously expressed in mesenchymal cells such as fibroblasts, smooth muscle cells, and endothelium. It is usually co-expressed with cytokeratin in some epithelial cells such as Sertoli cells. Vimentin expression may change as a tumor becomes more aggressive, as in the case of hyperplastic prostate where prostatic intraepithelial neoplasia strongly expresses vimentin (91%), but invasive carcinoma is minimally reactive with Mouse anti-Vimentin. Vimentin is useful as part of an antibody panel for differential diagnostic purposes. It may be included in an antibody panel for differentiating soft tissue tumors. For example, co-expression of vimentin and cytokeratin is indicative of epitheloid sarcoma. In one case, a differential antibody panel using vimentin, cytokeratin, CEA, and EMA distinguished reactive mesothelial cells from malignant epithelial cells in the cytodiagnosis of serous effusions in 39/46 cases (85%). The epitope has been localized on the alpha-helical part of vimentin (rod domain coil 2). Due to an aa substitution at position of aa 353 in murine vimentin (that could explain for the weak cross-reaction of the antibody with murine vimentin) they were able to narrow down the binding region around position 353. These findings were confirmed by truncation mutagenesis experiments using human vimentin Applications: Suitable for use in Immunohistochemistry, Immunofluorescence, ELISA and Western Blot. Other applications have not been tested. Recommended Dilution: Immunohistochemistry (Frozen and Paraffin): 1:100. Minimum of 1 hour incubation. Longer for paraffn sections. Protease pretreatment is recommended for paraffin sections. Optimal dilutions to be determined by the researcher. Recommended Control: Cultured RD cells, glioma cells, fibroblasts (SV-80), MDCK. Tumors specifically detected: sarcoma (including myosarcoma), lymphoma, melanoma. Storage and Stability: Lyophilized and reconstituted products are stable for 12 months after receipt at -20C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
