Fluorescent Proteins, Nucleotides & Other Conjugates

A high affinity inhibitor of the nicotinic acetylcholine receptor in the neuromuscular junction. Blocks acetylcholine activity at the postsynaptic membrane. The biotin conjugate can be subsequently labeled with anti-biotin antibodies, avidin, or streptavidin for signal amplification.

BrdU (5-Bromo-2′-deoxyuridine) can be incorporated into DNA during cell division and subsequently detected by a BrdU antibody. The probe can be used to study cell-cycle kinetics (1).

BrUTP (5-Bromouridine-5′-triphosphate) can be enzymatically incorporated into RNA and detected with anti-BrdU antibodies.

Calcein is a highly negatively charged, water-soluble fluorescein derivative. Its fluorescence is nearly independent of pH in the range between 6.5 and 12.

Calcein AM is a widely used green fluorescent cell marker. Calcein AM is membrane-permeant and thus can be introduced into cells via incubation.

5-(and-6)-Carboxy-2′,7′-dichlorofluorescein diacetate is membrane-permeant and thus can be loaded into cells via incubation. The diacetate is readily hydrolyzed to 5-(and-6)-carboxy-2′,7′-dichlorofluorescein (51015) by intracellular esterases.

CF® Dye biocytin is a cell-impermeant, fixable polar tracer that is a conjugate of CF® Dye and biotin with an aldehyde-fixable primary amine. Polar tracers are commonly used to investigate cell-cell and cell-liposome fusion as well as membrane permeability and transport through gap junctions or cell uptake during pinocytosis.

A fluorescently labeled cAMP analog that can be used to probe cAMP receptors.

CF® dye dCTP can be used to synthesize labeled DNA probes for in-situ hybridization, microarray or blotting applications.

DEAC-dUTP (diethylaminocoumarin-dUTP) can be used to synthesize fluorescent DNA probes for in situ hybridization, microarray or blotting techniques. DEAC has absorption at 426 nm and emission at 480 nm.

Digoxigenin-dUTP can be enzymatically incorporated into DNA via nick translation, random priming, or 3′-end terminal labeling to synthesize labeled DNA probes for in-situ hybridization, microarray or blotting techniques.  The digoxigenin labeled probe could be detected by using fluorescent labeled or enzyme labeled anti-digoxigenin antibody.

The principle of DPA/Tb³ for vesicle fusion assay is based on the fact that contact of the chelator dipicolinic acid (DPA) with terbium (III) forms an instant Tb³ -DPA complex that is ~10,000 times more fluorescent than free Tb³ . In the assay, separate vesicle populations are loaded with 2.5 mM TbCl3 in 50 mM sodium citrate, or 50 mM DPA in 20 mM NaCl.

DPX is a positively charged quencher that is often used with ANTS (90010) to study membrane fusion or permeability.

Fluorescein biotin (5-((N-(5-(N-(6-(Biotinoyl)amino)hexanoyl)amino)pentyl)thioureidyl) fluorescein) can be used to detect and quantify biotin binding sites and the degree of biotinylation of proteins. Also see biotin-rhodamine 110 (80022) and biotin-4-fluorescein (90062).

Fluorescein-12-dUTP can be used to synthesize fluorescent DNA probes.

Fluorescein-DHPE is a useful surface pH indicator, and has also been used for measuring lateral diffusion in membranes.