iFluor® 405–dextran conjugate (average molecular weight ~70,000 Da) is a high molecular weight, water-soluble fluorescent tracer designed for advanced studies of extracellular transport dynamics. This reagent consists of a 70 kDa dextran backbone covalently conjugated to iFluor® 405, a blue-fluorescent dye with excitation and emission maxima at approximately 403 nm and 427 nm, respectively. The substantial size of the 70 kDa dextran significantly restricts cellular uptake and endocytosis, making it particularly valuable for investigating vascular permeability, interstitial diffusion, and paracellular transport in both in vitro and in vivo models.

The iFluor® 405 fluorophore is spectrally similar to Pacific Blue® and is compatible with standard 405 nm laser excitation used in flow cytometry and fluorescence microscopy. It offers high photostability and strong fluorescence intensity, ensuring accurate and reproducible signal detection even under extended imaging conditions. Supplied as a lyophilized powder, the conjugate dissolves readily in aqueous solutions and is well-suited for use in live animal imaging, perfusion studies, and fluid-phase tracer experiments that require high molecular weight, non-permeable fluorescent markers.