"Biotium"

Supplier: Biotium

CD8 is a cell surface receptor expressed either as a heterodimer with the CD8 β chain (CD8 α/β) or as a homodimer (CD8 α/α). A majority of thymocytes and a subpopulation of mature T cells and NK cell express CD8a. CD8 binds to MHC class 1 and through its association with protein tyrosine kinase p56lck plays a role in T cell development and activation of mature T cells. For mature T-cells, CD4 and CD8 are mutually exclusive, so anti-CD8, generally used in conjunction with anti-CD4. It is a useful marker for distinguishing helper/inducer T-lymphocytes, and most peripheral T-cell lymphomas are CD4 /CD8-. Anaplastic large cell lymphoma is usually CD4 and CD8-, and in T-lymphoblastic lymphoma/leukemia, CD4 and CD8 are often co-expressed. CD8 is also found in littoral cell angioma of the spleen.

Supplier: Biotium

A disulphide-linked heterodimer, consisting of mb-1 (or CD79a) and B29 (or CD79b) polypeptides, is non-covalently associated with membrane-bound immunoglobulins on B cells. This complex of mb-1 and B29 polypeptides and immunoglobulin constitute the B cell Ag receptor. CD79a first appears at pre B cell stage, early in maturation, and persists until the plasma cell stage where it is found as an intracellular component. CD79a is found in the majority of acute leukemias of precursor B cell type, in B cell lines, B cell lymphomas, and in some myelomas. It is not present in myeloid or T cell lines. Anti-CD79a is generally used to complement anti-CD20 especially for mature B-cell lymphomas after treatment with Rituximab (anti-CD20). This antibody will stain many of the same lymphomas as anti-CD20, but also is more likely to stain B-lymphoblastic lymphoma/leukemia than is anti-CD20. Anti-CD79a also stains more cases of plasma cell myeloma and occasionally some types of endothelial cells as well.

Supplier: Biotium

Recognizes an oncofetal antigen of 220 kDa, identified as a tumor-associated glycoprotein (TAG-72) with properties of a mucin. This MAb defines the mucin-carried sialylated-Tn epitope. TAG-72 is usually expressed by adenocarcinomas, but is negative in mesotheliomas. Studies have reported that this antibody has 80% sensitivity and 93% specificity for pulmonary adenocarcinoma. Therefore, TAG-72 is a useful marker to distinguish between mesothelioma and adenocarcinoma. However, false positive reactions can occur so results must be interpreted with the utmost caution. This antibody may be useful in the differentiation of non-small cell carcinomas from small cell carcinomas of the lung. The combined use of anti-TAG-72 and anti-GCDFP-15 is valuable in the diagnosis of apocrine carcinoma.

Supplier: Biotium

The onset of angiogenesis is believed to be an early event in tumorigenesis and may facilitate tumor progression and metastasis. Several growth factors with angiogenic activity have been described. These include Fibroblast Growth Factor (FGF), Platelet Derived Growth Factor (PDGF), Vascular Endothelial Growth Factor (VEGF) and Placenta Growth Factor (PLGF). Placenta growth factor (PLGF) is a secreted protein primarily produced by placental trophoblasts but also expressed in other endothelial cells and tumors. There are three isoforms, PLGF-1, PLGF-2, and PLGF-3. PLGF-2 is expressed up until week 8 in the placenta; the placental tissues continuously express PLGF-1 and PLGF-3 but only PLGF-1 is found in colon and mammary carcinomas. PLGF acts to stimulate angiogenesis, endothelial growth and migration. PLGF is a powerful promoter of tumor growth and is upregulated in some cancers, and PLGF is thought to aid in atherosclerotic lesions and neovascular growth surrounding the lesion. Also, PLGF appears to aid aldosterone mediated atherosclerosis. Serum levels of PLGF in some cases are used as a potential biomarker for disease or genetic defect. Recent research indicates that PLGF levels are lower in mothers with Down syndrome fetuses. Evidence has suggested VEGF to be an obligatory component in PLGF signaling. While VEGF homodimers and VEGF/PLGF heterodimers function as potent mediators of mitogenic and chemotactic responses in endothelial cells, PLGF homodimers are effectual only at extremely high concentrations. Indeed, many of the physiological effects attributed to VEGF may actually be a result of VEGF/PLGF. VEGF and PLGF share a common receptor, Flt-1, and may also activate Flk-1/KDR.

Supplier: Biotium

This MAb recognizes a 21 kDa protein, identified as the p21WAF1 tumor suppressor protein. This MAb is highly specific to p21 and shows no cross-reaction with other closely related mitotic inhibitors. p21WAF1 is a specific inhibitor of cdk s and a tumor suppressor involved in the pathogenesis of a variety of malignancies. The expression of this gene acts as an inhibitor of the cell cycle during G1 phase and is tightly controlled by the tumor suppressor protein p53. Its expression is induced by the wild type, but not mutant, p53 suppressor protein. Normal cells generally display a rather intense nuclear p21 expression. Loss of p21 expression has been reported in many carcinomas (gastric carcinoma, non-small cell lung carcinoma, thyroid carcinoma). In ELISA, MAb WA-1 is useful either as a solid phase or for detection of p21 protein.

Supplier: Biotium

Myogenin is a member of the MyoD family of myogenic basic helix-loop-helix (bHLH) transcription factors that also includes MyoD, Myf-5, and MRF4 (also known as herculinor Myf-6). MyoD family members are expressed exclusively in skeletal muscle and play a key role in activating myogenesis by binding to enhancer sequences of muscle-specific genes. The regulatory domain of MyoD is approximately 70 amino acids in length and includes both a basic DNA binding motif and a bHLH dimerization motif. MyoD family members share about 80% amino acid homology in their bHLH motifs. Anti-myogenin labels the nuclei of myoblasts in developing muscle tissue, and is expressed in tumor cell nuclei of rhabdomyosarcoma and some leiomyosarcomas. Positive nuclear staining may occur in Wilms' tumor.

Supplier: Biotium

This MAb reacts with a wide variety of simple epithelia. It does not react with stratified squamous epithelia. It reacts with epithelial tumors of the gastrointestinal tract, lung, breast, pancreas, ovary, and thyroid. Cytokeratin 18, which belongs to the type A (acidic) subfamily of low molecular weight keratins, exists in combination with cytokeratin 8. It is reported that tissues from gastrointestinal tract are positive for both cytokeratin 8 and 18 but do not contain cytokeratin 14. Tissues from gastrointestinal tract, respiratory tract and urogenital tract, as well as endocrine and exocrine tissues and mesothelial cells are positive for cytokeratin 18.

Supplier: Biotium

This antibody recognizes a ~90-95 kDa protein which is identified as cell surface transferrin receptor (CD71), a disulfide-bonded homodimeric glycoprotein of 180-190 kDa. This MAb is highly specific to CD71 and shows no cross-reaction with other related proteins. Ligand for transferrin receptor is the serum iron transport protein, transferrin. This receptor is broadly distributed in carcinomas, sarcomas, leukemias, and lymphomas. CD71/Transferrin receptor has been reported to be associated with cell proliferation in both normal and neoplastic tissues and useful in predicting clinical behavior or response to therapy in a number of malignancies including breast cancer.

Supplier: Biotium

This MAb reacts with a 200 kDa and 68 kDa protein, identified as heavy and light sub-units of neurofilaments (NF-H & NF-L). Neurofilaments make up the main structural elements of axons and dendrites and are found in neurons, peripheral nerves, and sympathetic ganglion cells. Neurofilaments consist of three major subunits with molecular weights of 68 kDa (NF-L), 160 kDa (NF-M) and 200 kDa (NF-H). Anti-neurofilament stains a number of neural, neuroendocrine, and endocrine tumors. Neuromas, ganglioneuromas, gangliogliomas, ganglioneuroblastomas, and neuroblastomas stain positively for anti-neurofilament. Neurofilaments are also present in paragangliomas as well as adrenal and extra-adrenal pheochromocytomas. Carcinoids, neuroendocrine carcinomas of the skin, and oat cell carcinomas of the lung also express neurofilament.

Supplier: Biotium

In Western blotting, this antibody recognizes proteins in MW range of 265-400 kDa, identified as different glycoforms of EMA. This MAb reacts with the DTRP epitope in the tandem repeats. The α subunit has cell adhesive properties. It can act both as an adhesion and an anti-adhesion protein. EMA may provide a protective layer on epithelial cells against bacterial and enzyme attack. The β subunit contains a C-terminal domain, which is involved in cell signaling, through phosphorylations and protein-protein interactions. In immunohistochemical assays, it superbly stains routine formalin/paraffin carcinoma tissues. Antibody to EMA is useful as a pan-epithelial marker for detecting early metastatic loci of carcinoma in bone marrow or liver.

Supplier: Biotium

Recognizes an oncofetal antigen of 220 kDa, identified as a tumor-associated glycoprotein (TAG-72) with properties of a mucin. This MAb defines the mucin-carried sialylated-Tn epitope. TAG-72 is usually expressed by adenocarcinomas, but is negative in mesotheliomas. Studies have reported that this antibody has 80% sensitivity and 93% specificity for pulmonary adenocarcinoma. Therefore, TAG-72 is a useful marker to distinguish between mesothelioma and adenocarcinoma. However, false positive reactions can occur so results must be interpreted with the utmost caution. This antibody may be useful in the differentiation of non-small cell carcinomas from small cell carcinomas of the lung. The combined use of anti-TAG-72 and anti-GCDFP-15 is valuable in the diagnosis of apocrine carcinoma.

Supplier: Biotium

This MAb reacts with the HLA-DR antigen, a member of MHC class II molecules. It does not cross react with HLA-DP and HLA-DQ. HLA-DR is a heterodimeric cell surface glycoprotein comprised of a 36 kDa alpha (heavy) chain and a 28 kDa beta (light) chain. It is expressed on B-cells, activated T-cells, monocytes/macrophages, dendritic cells and other non-professional APCs. In conjunction with the CD3/TCR complex and CD4 molecules, HLA-DR is critical for efficient peptide presentation to CD4 T cells. It is an excellent histiocytic marker in paraffin sections producing intense cytoplasmic staining. True histiocytic neoplasms are similarly positive. HLA-DR antigens also occur on a variety of epithelial cells and their corresponding neoplastic counterparts.

Supplier: Biotium

Recognizes proteins of 33, 35 and 41 kDa, which are identified as various isoforms of CD74. Its epitope is localized in the extracellular domain of CD74. CD74 is a type II transmembrane protein which binds to the peptide binding groove of newly synthesized MHC class II alpha/beta heterodimers and prevents their premature association with endogenous polypeptides. The CD74 molecule plays a critical role in the presentation of peptides, by the MHC class II antigens, to CD4 positive lymphocytes. CD74 is expressed on MHC class II positive cells including B cells, a subset of activated T cells, monocytes, and dendritic cells and by various types of carcinomas. CD74 is expressed primarily by antigen presenting cells, such as B-lymphocytes (from before the pre-B cell stage to before the plasma cell stage), macrophages, and monocytes, and many epithelial cells. Anti-CD74 stains predominantly germinal center lymphocytes and B-cell lymphomas, but rarely T-cell lymphomas. Anti-CD74 has been shown to be useful in differentiating atypical fibroxanthoma (-) from malignant fibrous histiocytoma ( ).

Supplier: Biotium

Recognizes a protein of ~55 kDa, identified as SOX10. This MAb is highly specific and does not cross-react with other members of the SOX-family. SOX genes comprise a family of genes that are related to the mammalian sex-determining gene SRY. These genes similarly contain sequences that encode for the HMG-box domain, which is responsible for the sequence-specific DNA-binding activity. SOX-10 is a sensitive marker of melanoma, including conventional, spindled, and desmoplastic subtypes. It is expressed by metastatic melanomas and nodal capsular nevus in sentinel lymph nodes, but not by other lymph node components such as dendritic cells, which usually express S100 protein. Commonly used melanoma markers, such as anti-HMB-45 and anti-Melan-A, are poorly expressed in desmoplastic melanomas while SOX-10 is moderately to strongly expressed in desmoplastic melanomas. SOX-10 is considered as a very reliable marker for recognizing residual desmoplastic melanomas. In normal tissues, it is expressed in Schwann cells, melanocytes, and myoepithelial cells of salivary, bronchial and mammary glands. SOX-10 expression is also observed in mast cells.

Supplier: Biotium

This antibody recognizes an intermediate filament protein (IFP) of 55 kDa, which is identified as cytokeratin 7. This MAb is highly specific to cytokeratin 7 and shows no cross-reaction with other IFPs. Cytokeratin 7 is a basic cytokeratin, which is found in most glandular and transitional epithelia but not in the stratified squamous epithelia. Keratin 7 is expressed in the epithelial cells of ovary, lung, and breast but not of colon, prostate, or gastrointestinal tract. This MAb is highly useful in distinguishing ovarian carcinomas (keratin 7 ) from colon carcinomas (keratin 7-).

Supplier: Biotium

This antibody recognizes a glycoprotein of 75 kDa, identified as low affinity Nerve Growth Factor (NGF) Receptor (p75NGFR) or Neurotrophin Receptor (p75NTR). NGFR is expressed in various neural crest cells and their tumors such as melanocytes, melanomas, neuroblastomas, pheochromocytomas and neurofibromas. Reportedly, anti-NGFR is a reliable marker for desmoplastic and neurotropic melanomas. NGFR is expressed in mature non-neural cells such as perivascular cells, dental pulp cells, lymphoidal follicular dendritic cells, basal epithelium of oral mucosa and hair follicles, prostate basal cells, and myoepithelial cells. Anti-NGFR stains the myoepithelial cells of breast ducts and intra-lobular fibroblasts of breast ducts.