Invitrogen™ Dextran, Alexa Fluor™ 555; 10,000 MW, Anionic, Fixable

Labeled dextrans are hydrophilic polysaccharides most commonly used in microscopy studies to monitor cell division, track the movement of live cells, and to report the hydrodynamic properties of the cytoplasmic matrix. The labeled dextran is commonly introduced into the cells via microinjection. Dextrans are hydrophilic polysaccharides characterized by their moderate-to-high molecular weight, good water solubility, and low toxicity. They also generally exhibit low immunogeniticy. Dextrans are biologically inert due to their uncommon poly-(α-D-1,6-glucose) linkages, which render them resistant to cleavage by most endogenous cellular glycosidases.

• Succinimidyl coupling of dyes to dextran molecule, which, in most cases, results in neutral or anionic dextran
• Reaction used to produce Rhodamine Green™ and Alexa Fluor™ 488 dextrans results in final product being neutral, anionic, or cationic
• Suitable for neuronal tracing (anterograde and retrograde) in live cells
• Cell lineage tracing in live cells
• Examines intercellular communications (e.g., in gap junctions, during wound healing, and during embryonic development)
• Investigates vascular permeability and blood-brain barrier integrity
• Monitors acidification (some dextran-dye conjugates are pH-sensitive)
• Studies hydrodynamic properties of cytoplasmic matrix

• Alexa Fluor dextrans are intrinsically anionic
• To produce more highly anionic dextrans, proprietary procedure adds negatively charged groups to dextran carriers; these products are designated polyanionic dextrans
• Some applications require that dextran tracer be treated with formaldehyde or glutaraldehyde for subsequent analysis: For these applications, lysine-fixable dextran conjugates of fluorophores or biotin
• Dextrans have covalently bound lysine residues that permit dextran tracers to be conjugated to surrounding biomolecules by aldehyde-mediated fixation for subsequent detection by immunohistochemical and ultrastructural techniques
• 10,000 MW Alexa Fluor dextran conjugates can be fixed with aldehyde-based fixatives

Cell Analysis, Cell Tracing and Tracking, General Cell Tracing, Neuronal Tracing