Antibody biotin

An interleukin ELISA kit comprising a capture antibody, biotin-labelled secondary antibody, and interleukin IB (IL-1B, part 840170, R D Systems, Abingdon, UK). 

Secondary antibody biotin-labeled goat anti-mouse immunoglobulin (Vector Laboratories, Burlingame, CA), at appropriate dilution. 

A Antibody Biotin C Streptavidin m p-Galactosidase Qdot wheat germ agglutinin... 

Phosphotyrosine RC20 monoclonal antibody Biotin conjugate (Pharmingen, Cat. No. 610021). 

Imaging/Labeling Applications Amines/amino groups antibodies " biotin ceUs/tissues chromosomes cyclodextrin/dextran " ... 

Chemiluminescent Immunoassay. Chemiluminescence is the emission of visible light resulting from a chemical reaction. The majority of such reactions are oxidations, using oxygen or peroxides, and among the first chemicals studied for chemiluminescence were luminol (5-amino-2,3-dihydro-l,4-phthalazinedione [521-31-3]) and its derivatives (see Luminescent materials, chemiluminescence). Luminol or isoluminol can be directly linked to antibodies and used in a system with peroxidase to detect specific antigens. One of the first appHcations of this approach was for the detection of biotin (31). 

Fig. 34 Functionalisation of bait peptides. I Gold-labelled streptavidin is attached directly. 2 Biotin-labelled anti-FLAG antibody is bound to the FLAG on the peptide (reaction b) and this is used to attach gold-labelled streptavidin (reaction d). Reprinted with permission from Ryadnov and Woolfson [76]. Copyright 2004 American Chemical Society...

Figure 3. E. chrysanthemi cell surface labelling with sulfo-NHS-biotin. After labelling, the proteins were separated by SDS-PAGE, blotted onto nitrocellulose and revealed with PemB-antibodies (A) or with streptavidin-peroxidasc (B). Lane 1 A350 (wild type) lane 2 A837 kdgRy, lane 3 A350/pPME6. An arrowhead indicates the PemB position.

The LANCE cAMP assay is a competitive assay in which cAMP produced by the cells competes with fluorescent-labeled acceptor cAMP for a cryptate tagged donor antibody. The principal of the assay is shown in Fig. 6. On the left strepta-vidin conjugated Europium binds to biotinylated cAMP. An antibody labeled with the fluorescent dye Alexa binds to the cAMP, bringing the donor and acceptor into close proximity, and energy transfer occurs. When the cell releases cAMP, it competes with the biotin-labeled cAMP for the antibody, and a signal decrease is observed. In the TR-FRET assay the antibody is directly labeled with either Eu or Tb. In this format an increase in cAMP also causes a decrease in signal. 

Recently, SETA BioMedicals has developed a new near-infrared squaraine-based label Seta-633, which can be used to study the interaction between low-molecular-weight analytes and proteins using fluorescence lifetime as the readout parameter [19]. This label exhibits lower quantum yields and shorter fluorescence lifetimes when free in solution, but these values substantially increase upon interaction with proteins, which is contrary to tracers like Cy5 or Alexa 647. It was demonstrated in a model assay that a biotinylated Seta-633 binds to anti-biotin with high specificity. Importantly, the lifetime of Seta-633-biotin increases about 2.76 fold upon binding to a specific antibody (anti-biotin, MW =160 kDa), while the titration with BSA or nonspecific antibody does not result in a noticeable change in lifetime (Fig. 13). The label is compatible with readily available light sources (635 nm or 640 nm lasers) and filter sets (as for Cy5 or Alexa 647) and its... 

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