Blog

  • Whitepaper: LBP as an Indicator of Disease States

    Lipopolysaccharide-Binding Protein (LBP) as an Indicator of Disease States in Multiple Species

    Amanda Flies, Ph.D. and Thomas H. Ermak, Ph.D.

    LBP-activity

    LBP binds multimers of LPS in the blood or other bodily fluids and transfers LPS monomers to CD14 on the surface of an innate immune cell. LPS is detected at the cell’s surface by a protein complex involving CD14, MD2 and TLR4, which signals through its intracellular domain. Recognition of bacterial products such as LPS may activate innate immune cells to produce inflammatory mediators.

    Abstract
    Lipopolysaccharide binding protein (LBP) is a 58-kD glycoprotein involved in the acute-phase immunologic response to Gram-negative bacterial infections. It binds with high affinity to the lipid A portion of lipopolysaccharide (LPS), which Gram-negative bacteria express on their outer membrane. The presence of LBP in blood and bodily fluids is an indicator of bacterial infection, and as such is a useful marker of a number of disease states in humans, cows, mice and other animals.
    As a method of detecting this important acute-phase protein, ELISA (enzyme-linked immunosorbent assay) offers specificity and reliable quantitation of the protein levels in samples such as blood, serum, lavage fluid, or milk. The Cell Sciences® Multispecies LBP ELISA kit maintains specificity for human LBP, while also providing flexibility to assess a broad range of LBP homologs in other species.

    Click here to download the full pdf.

    LBP Reagents offered by Cell Sciences

    CKH113  Human LBP Multispecies Reactive ELISA Kit

    CKM043  Mouse LBP ELISA Kit

    CML002  Mouse Anti-Human LBP Clone biG 42 mAb†

    CML003  Mouse Anti-Human LBP Clone biG 48 mAb†

    CML004  Mouse Anti-Human LBP Clone biG 412 mAb*

    CML007  Mouse Anti-Human LBP Clone biG 43 mAb†

    CPC402A  Rabbit Anti-Human LBP pAb

    CML001  Mouse Anti-Mouse LBP Clone biG 33 mAb*

    CML005  Mouse Anti-Mouse LBP Clone biG 35 mAb†

    CPC105  Rabbit Anti-Mouse LBP pAb

    CRL701  Recombinant Human LBP

    CRL700  Recombinant Mouse LBP

    * Inhibits binding to CD14        † Does not inhibit binding to CD14

     

  • Whitepaper: Quantitation of LONG®R3 IGF-I

    Quantitation of LONG®R3 IGF-I during production and purification of recombinant proteins from cell culture

    Thomas H. Ermak, Ph.D. and Amanda Flies, Ph.D.

    This paper discusses the use of a recently developed ELISA kit to measure the IGF1 analog LONG®R3 IGF-I in mammalian cell culture media during the production of recombinant proteins. The structures of LONG®R3 IGF-I, Native IGF1 and Insulin are compared, and an immunoassay for the quantitation of LONG®R3 IGF-I is described.

    Long-LR3-IGF1

    Abstract
    LONG®R3 IGF-I is an analog of human insulin-like growth factor 1 that has been bioengineered for use in cell culture during production of recombinant proteins in human cells. LONG®R3 IGF-I comprises the 70 amino acids of IGF-1 with an arginine substitution for glutamic acid at amino acid 3 and a 13 amino acid extension peptide at the N-terminal end for a total of 83 amino acids. LONG®R3 IGF-I has a lower affinity for IGF binding proteins increasing its bioavailability to the IFG-1 receptor present on cells in culture. When supplemented in serum-free medium, it promotes cell proliferation and increases cell survival and productivity through better proliferative and anti-apoptotic signaling. A LONG®R3 IGF-I ELISA kit was recently developed to monitor the levels of LONG®R3 IGF-I in culture medium during the production process. The assay measures concentrations of LONG®R3 IGF-I in the 0.31 to 40 ng/ml range. The ready-to-use ELISA kit facilitates measurement of LONG®R3 IGF-I during optimization of the cell culture process and downstream processing purification.

    Download the full whitepaper here

    LONG®R3 IGF-I ELISA and Related Products

    CKH194 Human LONG®R3 IGF-I ELISA Kit
    CRH060 LONG®R3 IGF-I (Recombinant Human) Lyophilized
    CRH061 LONG®R3 IGF-I (Recombinant Human) Liquid
    MAN100 Mouse Anti-Human LR3 IGF-1 Clone 6H5 mAb
    MAO100 Mouse Anti-Human LR3 IGF-1 Clone 1A7 Biotin mAb

    LONG® is a trademark of Repligen Corporation.

  • CD14 and LBP Products

    CD14 and LBP: ELISA kits, recombinant proteins, monoclonal and polyclonal antibodies

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    CD14:
    CD14 is the 53-kD glycophosphatidylinositol (GPI)-linked glycoprotein and functions as high affinity endotoxin (LPS) receptor on the surface of monocytes, macrophages and granulocytes as well as brain cells. Together with TLR4 and a lymphocytic antigen (MD2) CD14 is the lipopolysaccharide (LPS)-Receptor and mediates innate immune response to bacterial lipoproteins. In the presence of LPS, CD14-expression can be amplified by TNF-alpha and IL-1 beta. CD14 is present in a soluble form in human serum, urine and other body fluids which is directly secreted or derived from protease-dependent shedding of the membrane bound molecule. Soluble CD14 (sCD14) competes with membrane bound CD14 (mCD14) for LPS binding and is able to neutralize LPS-induced responses in vitro and in vivo and mediates the LPS-induced activation of non-CD14-expressing endothelial, epithelial and smooth-muscle cells.

    CD14 Reagents

    CKH114  Human sCD14 ELISA Kit

    CKM034  Mouse sCD14 ELISA Kit

    CDM150  Mouse Anti-Human CD14 Clone B-A8 Azide Free mAb

    CMC000  Mouse Anti-Human CD14 Clone biG 10 mAb

    CMC001  Mouse Anti-Human CD14 Clone biG 13 multispecies mAb

    CMC005  Mouse Anti-Mouse CD14 Clone biG 53 mAb

    CRCC01  Recombinant Human CD14

    CRCC03  Recombinant Mouse CD14


     

    LBP:
    LBP (Lipopolysaccharide binding protein) is a 58-kD acute phase glycoprotein, binds to the lipid A portion of Lipopolysaccharide (LPS) with high affinity and catalyzed the CD14 and TLR4 dependent cellular activation by LPS. LBP interacted with CD14, TLR2, TLR4 und the co-receptor MD-2. LBP is involved in the acute-phase immunologic response to gram-negative bacterial infections. Gram-negative bacteria contain LPS on their outer cell wall. Together with bactericidal permeability-increasing protein (BPI), LBP binds LPS and interacts with the CD14 receptor, probably playing a role in regulating LPS-dependent monocyte responses.

    LBP Reagents

    CKH113  Human LBP Multispecies Reactive ELISA Kit

    CKM043  Mouse LBP ELISA Kit

    CML002  Mouse Anti-Human LBP Clone biG 42 mAb†

    CML003  Mouse Anti-Human LBP Clone biG 48 mAb†

    CML004  Mouse Anti-Human LBP Clone biG 412 mAb*

    CML007  Mouse Anti-Human LBP Clone biG 43 mAb†

    CPC402A  Rabbit Anti-Human LBP pAb

    CML001  Mouse Anti-Mouse LBP Clone biG 33 mAb*

    CML005  Mouse Anti-Mouse LBP Clone biG 35 mAb†

    CPC105  Rabbit Anti-Mouse LBP pAb

    CRL701  Recombinant Human LBP

    CRL700  Recombinant Mouse LBP

    * Inhibits binding to CD14        † Does not inhibit binding to CD14

  • Prion Proteins Research Antibody

    Anti-prion antibody for use in research applications, clone 1E4:

    Sanquin Reagents, in cooperation with the research division of Sanquin, has developed a monoclonal anti-prion antibody for use in research applications: clone 1E4. The antibody is available form Cell Sciences in unconjugated form as well as biotin conjugated or HRP conjugated (see below).

    Item M1839: Anti-Prion, clone 1E4, Monoclonal Antibody
    Item M1840: Biotinylated Anti-Prion, clone 1E4, Monoclonal Antibody
    Item M1841: HRP Conjugated Anti-Prion, clone 1E4, Monoclonal Antibody

    Background Information
    The term “prion” was introduced by Stanley Prusiner in 1982 to describe the atypical infectious agent that causes transmissible spongiform encephalopathies, a group of infectious neurodegenerative diseases that include scrapie in sheep, Creutzfeldt-Jakob disease in humans, chronic wasting disease (CWD) in deer, and bovine spongiform encephalopathy (BSE) in cattle.

    The ‘mad cow’ crisis has drawn a lot of attention to prion diseases. Significant progress has been made in prion disease research, and many aspects of prion pathogenesis are now understood. And yet the diagnostic procedures available for prion diseases are not nearly as sensitive as they ought to be, i.e. a diagnostic test to proof the presence of pathogenic prion in blood or serum.

    Special Features of 1E4
    In contrast to many other anti-prion antibodies, mAb 1E4 has a broad species reactivity. This enables the detection of prion proteins in biological samples of many species including mouse adapted BSE (301V)-infected mice, scrapie-infected sheep, scrapie infected hamster (263K), CWD infected deer, sCJD- and vCJD-infected human on Western blots.

    Most of the currently available TSE tests are based on the fact that PrPC, normal prion protein, is digested by Protease K, whereas PrPSc, TSE specific prion, is relatively resistant to degradation by proteases. The special feature of mAb 1E4 is where the PrPSc epitope binds, PrP27-30, which is mostly hidden on non-digested prion proteins. After Proteinase K digestion the epitope becomes better available on proteinase resistant PrPSc, resulting in a significant signal increase. After digestion with Protease K , mAb 1E4 binds to PrPSc with a high affinity, whereas it has a low affinity for non-digested PrPSc. This makes mAb 1E4 a highly interesting antibody in current prion disease research.

    Applications
    1E4 has been tested in a broad variety of methods, such as Western blot, RIA, ELISA, EliBlot, FACS and immunohistochemistry. 1E4 allows prion research in many immunological techniques across a broad range of species.

    REFERENCE:
    Prusiner, S.B., Prions, Proc. Natl. Acad. Sci., Vol.95, pp 13363 - 13383, 1998.