Phycoerythrin streptavidin conjugate

The effects of CVS on the numbers of T-cell subsets were examined on day 9 at the time of tumor i.v. rechallenging, Fig. (6)-Protocol B. Cells were stained with fluorescein 5-isothiocyanate (FITC)-, phycoerythrin (PE)-conjugated and/or biotinylated mAb and were additionally stained with RED-613-streptavidin for flow-cytometric three-color analysis. 

Naegleria fowleri (Pougnard et al. 2002) has been detected by SPC in surface water. A monoclonal antibody was conjugated with biotin or HRP and revealed by streptavidin conjugated to RPE-Cy5 (R-phycoerythrin conjugated with the cyanine dye Cy5) or FITC-conjngated tyramide, respectively. The RPE-Cy5 protocol was the most efficient and allowed the detection of both trophozoite and cyst forms in water. 

The spectral properties of four major phycobiliproteins used as fluorescent labels can be found in Tables 9.1 and 9.2. The bilin content of these proteins ranges from a low of four prosthetic groups in C-phycocyanin to the 34 groups of B- and R-phycoerythrin. Phycoerythrin derivatives, therefore, can be used to create the most intensely fluorescent probes possible using these proteins. The fluorescent yield of the most luminescent phycobiliprotein molecule is equivalent to about 30 fluoresceins or 100 rhodamine molecules. Streptavidin-phycoerythrin conjugates, for example, have been used to detect as little as 100 biotinylated antibodies bound to receptor proteins per cell (Zola et al., 1990). 

Fig. 5.2. Methods for detection of passenger-ligand interaction. (A) Fluorophore-coupled ligand (B) fluorophore-coupled antibody (C) quaternary complex generated by subsequent rounds of incubation with ligand, primary antibody, biotinylated second antibody, and strep ta-vidin, R-phycoerythrin conjugate (D) quaternary complex generated by subsequent rounds of incubation wi tli ligand, primary antibody, biotinylated second antibody, and streptavidin-coated magnetobeads. L ligand P passenger.

Streptavidin, R-phycoerythrin conjugate, lmgmL-1 (Molecular Probes). 

If the ligand protein is fluorescently labeled, resuspend the cells in 10 pL PBS and subject directly to FACS. If the ligand protein is biotinylated (protocol 2), resuspend the cells in 10 pL PBS containing streptavidin, R-phycoerythrin conjugate (1 10 dilution in PBS). Incubate on ice again for 10 min. 

Figu re 4.8 Flow cytometry analysis of silica nanoparticles surface-modified with proteins. MPMS nanoparticles (a, c) and TEOS nanoparticles (b, d) modified with GFP (a, b) or phycoerythrin-conjugated streptavidin... 

Avidin-biotin systems. Stable and highly active protein-LB/LS film composites can be accessed using avidin-biotin conjugation techniques. Thus, sensor elements displaying biotinylated GOx and phycoerythrin, and streptavidin and av-idin conjugates of phycoerj tiirin, have been bound to avidin-lipid and biotinylated lipid-streptavidin LB films, or biotinylated lipid layers have been produced [71-73]. 

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