There is no such thing as “one-size-fits-all” when it comes to NIR fluorophore labeling.
A targetting ligand that is hydrophilic and electrically neutral will exhibit drastically different in vivo behavior if conjugated to a NIR fluorophore that is anionic and hydrophobic. Similarly, if a ligand is hydrophobic, conjugating a hydrophilic NIR fluorophore will alter its behavior and performance. This is especially important for hydrophobic ligands that bind intracellular targets, where the NIR fluorophore must pass freely across the plasma membrane. Keep in mind, too, that for some small molecule ligands, the NIR fluorophore will be a large fraction of the total molecular weight of the final conjugate and could dominate its physicochemical behavior.
For these reasons, Curadel ResVet Imaging has developed Ligand-Match™, a family of NIR fluorophores that can solve virtually any labeling problem. Simply use the graphic above to select the best fluorophore for your project. Slide to the left or right to select desired hydrophibicity/hydrophilicity, then slide up or down to choose 700 nm emission (FLARE Channel #1) or 800 nm emission (FLARE Channel #2).
Example: You want to label an antibody fragment with a NIR fluorophore and image it at 700 nm. Slide to the right and down to choose ZW700-1 Forte, which is available as an NHS ester or a maleimide derivative, with or without PEG spacers, for one-step labeling.
Example: You want to label a ligand that binds to an intracellular protein complex and image it at 800 nm. Slide to the left and up to choose Lipo800 Forte,which is available as an NHS ester or a maleimide derivative, with or without PEG spacers, for one-step labeling.
NIR Fluorescent Antibodies
CRV has developed a unique and proprietary family of zwitterionic NIR fluorescent antibodies that are best-in-class. Featuring high signal and extremely low non-specific background, these antibodies can be used in virtually any in vitro or in vivo assay. NIR fluorescent antibodies are available against many different species and are labeled with a variety of zwitterionic NIR fluorophores having emission at either 700 nm (Lab-FLARE® channel 1) or 800 nm (Lab-FLARE® channel 2). Please use our Research Product Finder to quickly find the right one for your experiments.
Curadel ResVet Imaging’s “Anatomical Atlas” family of NIR fluorophores label or highlight various in vivo targets, especially those that are difficult to image. Use our Research Product Finder to find the right dye for your target. Almost all Anatomical Atlas contrast agents are available as either 700 nm (FLARE® Channel #1) or 800 nm (FLARE® Channel #2) so if needed, you can highlight two targets at once. Choose from dyes that label the thoracic duct, ureters, lymph nodes, sentinel lymph nodes, or cartilage to name a few. All Anatomical Atlas contrast agents are guaranteed to provide optimal results using the FLARE® Model R1 imaging system.
In Vivo Cell Tracking
Curadel ResVet Imaging has developed an entire family of proprietary lipophilic NIR fluorophores that cross the plasma membrane and lodge in the intracellular membranes of living cells. Depending on the cell type of interest, these dyes can be stable for days to weeks inside cells, and provided their final concentration is titrated carefully, should not disturb normal cellular physiology. They can be used to track cells in vitro and in vivo in a variety of research applications using the FLARE® imaging system. And, because two different fluorescence wavelengths (700 nm and 800 nm) are provided, two different cell types can be tracked independently. The first cell tracking products available are Lipo700 Forte and Lipo800 Forte. Forte dyes are ultrastable versions of conventional NIR fluorophores. In the near future we will be introducing additional cell tracking compounds that have special features.