1571 Results for: "ph buffer solutions"

Supplier: Prosci

Tumor Necrosis Factor Alpha (TNF alpha) is a protein secreted by lipopolysaccharide-stimulated macrophages, and causes tumor necrosis when injected into tumor bearing mice. TNF alpha is believed to mediate pathogenic shock and tissue injury associated with endotoxemia. TNF alpha exists as a multimer of two, three, or five non-covalently linked units, but shows a single 17kDa band following SDS PAGE under non-reducing conditions. TNF alpha is closely related to the 25kDa protein Tumor Necrosis Factor beta (lymphotoxin), sharing the same receptors and cellular actions. TNF alpha causes cytolysis of certain transformed cells, being synergistic with interferon gamma in its cytotoxicity. Although it has little effect on many cultured normal human cells, TNF alpha appears to be directly toxic to vascular endothelial cells. Other actions of TNF alpha include stimulating growth of human fibroblasts and other cell lines, activating polymorphonuclear neutrophils and osteoclasts, and induction of interleukin 1, prostaglandin E2 and collagenase production. TNF alpha is currently being evaluated in treatment of certain cancers and AIDS Related Complex.

Supplier: Prosci

Immunoglobulin gamma (IgG) is the most common class of antibody in blood and extracellular fluid. Approximately 75% of serum antibodies in humans are IgG. There are four immunoglobulin gamma subclasses: one, two, three and four. IgG1 is the most common, with 68% of all gamma class antibodies being G1, and G4 is the least common at 4%. Gamma class antibodies are found primarily in the secondary immune response, class switching from IgM and IgD. They are the only class of antibody that can cross the placenta, and along with IgA secreted in breast milk, provide the neonate with humoral immunity before immune system development occurs.

This antibody recognizes a protein of 75kDa identified as the gamma heavy chain of human immunoglobulins. It does not cross-react with alpha, mu, epsilon, or delta heavy chains, T-cells, monocytes, granulocytes, or erythrocytes. The IgG antibody is useful in the identification of leukemias, plasmacytomas, and certain non-Hodgkin's lymphomas. The most common feature of these malignancies is the restricted expression of a single heavy chain class. Demonstration of clonality in lymphoid infiltrates indicates that the infiltrate is clonal and therefore malignant.

Supplier: Prosci

Cytokeratin 8 is the product of the KRT8 gene and one of the most abundant keratins. The KRT8 gene is a member of the type II keratin family clustered on the long arm of chromosome 12. Cytokeratin 8 participates in cellular differentiation and signal transduction, protects against apoptosis, stress and injury, and helps maintain cellular structural integrity. It is primarily found in the non-squamous epithelia and is present in majority of adenocarcinomas and ductal carcinomas. It is absent in squamous cell carcinomas. Specific combinations of cytokeratins are associated with certain epithelial cells, and therefore useful in the characterization of poorly differentiated carcinoma. Hepatocellular carcinomas are defined by the use of antibody that recognizes only cytokeratin 8 and 18. Keratin 8 exists on several types of normal and neoplastic epithelia, including many ductal and glandular epithelia such as colon, stomach, small intestine, trachea, and esophagus as well as in transitional epithelium. Antibody to Cytokeratin 8 does not react with skeletal muscle or nerve cells. Epithelioid sarcoma, chordoma, and adamantinoma show strong positivity corresponding to that of simple epithelia (with antibodies against Keratin 8, 18 and 19). Reportedly, Cytokeratin 8 antibody is useful for the differentiation of lobular (ring-like, perinuclear) from ductal (peripheral-predominant) carcinoma of the breast.

Supplier: Prosci

CD45, also referred to as CD45R and PTPRC (Protein tyrosine phosphatase receptor type C), has been identified as a transmembrane glycoprotein, broadly expressed among hematopoietic cells. Along with other members of the PTP family, it regulates a number of cellular processes including cell differentiation, growth and mitotic cycle, and is an essential regulator of B- and T-cell antigen receptor-mediated activation.

Multiple isoforms of CD45 are distributed throughout the immune system and arise due to alternative splicing of exons located in the N-terminus. CD45RA contains the A exon and is a naive T-cell marker which may help prevent autoimmune disease. CD45RB contains B and stains most leukemias and lymphomas. CD45RC contains C and stains thymocytes, monocytes and dendritic cells. CD45RO doesn't contain A, B or C and is a marker of activated T-cells that can be used to classify and diagnose and classify lymphomas. This antibody will bind to all CD45 isoforms. The variation in these isoforms is localized to the extracellular domain, with the intracellular domain being conserved. Antibody to CD45 is useful in differential diagnosis of lymphoid tumors from non-hematopoietic undifferentiated neoplasms.

Supplier: Prosci

Recognizes a protein of 57kDa, identified as p57Kip2. It shows no cross-reaction with p27Kip1. p57Kip2 is a potent tight-binding inhibitor of several G1 cyclin complexes, and is a negative regulator of cell proliferation. Anti-p57 has been used as an aide in identification of complete hydatidiform mole (CHM) (no nuclear labeling of cytotrophoblasts and stromal cells) from partial hydatidiform mole (PHM) in which both cytotrophoblasts and stromal cells stain. The histological differentiation of complete mole, partial mole, and hydropic spontaneous abortion is problematic. Most complete hydatidiform moles are diploid, whereas most partial moles are triploid. Ploidy studies will identify partial moles, but will not differentiate complete moles from non-molar gestations. Complete moles carry a high risk of persistent disease and choriocarcinoma, while partial moles have a very low risk. In normal placenta, many cytotrophoblast nuclei and stromal cells are labeled with this antibody. Similar findings apply to PHM and hydropic abortus tissues. Intervillous trophoblastic islands (IVTIs) demonstrate nuclear labeling in all three entities and serve as an internal control.

Supplier: Prosci

Recognizes a protein of 57kDa, identified as p57Kip2. It shows no cross-reaction with p27Kip1. p57Kip2 is a potent tight-binding inhibitor of several G1 cyclin complexes, and is a negative regulator of cell proliferation. Anti-p57 has been used as an aide in identification of complete hydatidiform mole (CHM) (no nuclear labeling of cytotrophoblasts and stromal cells) from partial hydatidiform mole (PHM) in which both cytotrophoblasts and stromal cells stain. The histological differentiation of complete mole, partial mole, and hydropic spontaneous abortion is problematic. Most complete hydatidiform moles are diploid, whereas most partial moles are triploid. Ploidy studies will identify partial moles, but will not differentiate complete moles from non-molar gestations. Complete moles carry a high risk of persistent disease and choriocarcinoma, while partial moles have a very low risk. In normal placenta, many cytotrophoblast nuclei and stromal cells are labeled with this antibody. Similar findings apply to PHM and hydropic abortus tissues. Intervillous trophoblastic islands (IVTIs) demonstrate nuclear labeling in all three entities and serve as an internal control.

Supplier: Prosci

Mucin-1 is a large cell surface mucin glycoprotein expressed by most glandular and ductal epithelial cells and some hematopoietic cell lineages. It is expressed on most secretory epithelium, including mammary gland and some hematopoietic cells. It is expressed abundantly in lactating mammary glands and over expressed in >90% breast carcinomas and metastases. The transgenic protein has been shown to associate with all four c-erbB receptors and localize with c-erbB1 (EGFR) in lactating glands. The gene contains seven exons and produces several different alternatively spliced variants. The major expressed form of the protein uses all seven exons and is a type 1 transmembrane protein with a large extracellular tandem repeat domain. The tandem repeat domain is highly O glycosylated and alterations in glycosylation have been shown in epithelial cancer cells. Mucin-1 antibody is useful as a pan-epithelial marker for detecting early metastatic loci of carcinoma in bone marrow or liver. The specific epitope of this Mucin-1 antibody has not yet been determined.

Supplier: Prosci

Melanocytes produce organelles called melanosomes which produce melanin, the pigment that gives color to skin, hair, eyes, scales and feathers. gp100 was identified in an attempt to clone the gene Tyrosinase, an enzyme required for melanin synthesis. Further testing determined that gp100 is a melanoma-specific protein and is responsible for melanosome maturation, facilitating the transition from amorphous rounded vesicles to fibrillary ellipsoid organelles.
Metastatic amelanotic melanoma can often be confused with a variety of poorly differentiated carcinomas, large cell lymphomas, and sarcomas using H & E stains alone. It is also difficult to differentiate melanoma from spindle cell carcinomas and various types of mesenchymal neoplasms. Clone HMB45 gp100 antibody stains fetal and neonatal melanocytes, junctional and blue nevus cells, and malignant melanoma. It also stains angiomyolipomas, tumors most commonly associated with the kidney. Intradermal nevi, normal adult melanocytes, and non-melanocytic cells are negative. This gp100 antibody does not stain tumor cells of epithelial, lymphoid, glial, or mesenchymal origin.

Supplier: Prosci

Recognizes a protein of 57kDa, identified as p57Kip2. It shows no cross-reaction with p27Kip1. p57Kip2 is a potent tight-binding inhibitor of several G1 cyclin complexes, and is a negative regulator of cell proliferation. Anti-p57 has been used as an aide in identification of complete hydatidiform mole (CHM) (no nuclear labeling of cytotrophoblasts and stromal cells) from partial hydatidiform mole (PHM) in which both cytotrophoblasts and stromal cells stain. The histological differentiation of complete mole, partial mole, and hydropic spontaneous abortion is problematic. Most complete hydatidiform moles are diploid, whereas most partial moles are triploid. Ploidy studies will identify partial moles, but will not differentiate complete moles from non-molar gestations. Complete moles carry a high risk of persistent disease and choriocarcinoma, while partial moles have a very low risk. In normal placenta, many cytotrophoblast nuclei and stromal cells are labeled with this antibody. Similar findings apply to PHM and hydropic abortus tissues. Intervillous trophoblastic islands (IVTIs) demonstrate nuclear labeling in all three entities and serve as an internal control.

Supplier: Prosci

This mAb recognizes a protein of 134kDa, which binds fibroblast growth factor and E-selectin (cell-adhesion lectin on endothelial cells mediating the binding of neutrophils). Fucosylation is essential for binding to E-selectin. It contains sialic acid residues and 16 Cys-rich GLG1 repeats. This mAb can be used to stain the Golgi complex in cell or tissue preparations and can be used as a Golgi marker in subcellular fractions. It produces a diffuse staining pattern of the Golgi zone in normal and malignant cells. This mAb is an excellent marker for human cells in xenographic model research. It reacts specifically with human cells. The Golgi apparatus is an organelle present in all eukaryotic cells that forms a part of the endomembrane system. The primary function of the Golgi apparatus is to process and package macromolecules synthesized by the cell for exocytosis or use within the cell. The Golgi is made up of a stack of flattened, membrane-bound sacs known as cisternae, with three functional regions: the cis face, medial region and trans face. Each region consists of various enzymes that selectively modify the macromolecules passing though them, depending on where they are destined to reside. Several spherical vesicles that have budded off of the Golgi are present surrounding the main cisternae. The Golgi tends to be more pronounced and numerous in cells that make and secrete many substances such as plasma B cells.

Supplier: Prosci

Cytokeratin 17 (CK17) is a member of the Cytokeratin subfamily of intermediate filament proteins (IF's). It is unique in that it is normally expressed in the basal cells of complex epithelia but not in stratified or simple epithelia. CK17 is expressed in the nail bed, hair follicle, sebaceous glands and other epidermal appendages. Antibody to CK17 is an excellent tool to distinguish myoepithelial cells from luminal epithelium of various glands such as mammary, sweat and salivary. CK17 is expressed in epithelial cells of various origins, such as bronchial epithelial cells and skin appendages. It may be considered an epithelial stem cell marker because CK17 Ab marks basal cell differentiation. CK17 can be useful when included in a panel of antibodies against TTF-1, napsin A, CK5&6, p63, and SOX-2 for diagnostic differentiation between lung adenocarcinoma (LADC) and lung squamous cell carcinoma (SCLC), especially for poorly-differentiated lung carcinoma. CK17 is expressed in SCLC much higher than in LADC. In breast carcinomas, approximately 20% of patients show no expression of ER, PR and Her2, which are defined as triple negative tumor. Eighty-five percent of the triple negative breast carcinomas immunoreact with basal cytokeratins including anti-CK17. Also important is that cases of triple negative breast carcinoma with expression of CK17 show an aggressive clinical course. The histologic differentiation of ampullary cancer, intestinal vs. pancreatobiliary, is very important for treatment. Usually anti-CK17 and anti-MUC1 immunoreactivity represents pancreatobiliary subtype whereas anti-MUC2 and anti-CDX-2 positivity defines intestinal subtype.