Development and use of optical imaging agents that contain IRDye® 800CW coupled to other molecules require a control for potential effects or retention of the dye itself. The carboxylate form of IRDye 800CW is the ideal control, as it is in a non-reactive state. Note: The carboxylate dye has no reactive group and cannot be used for labeling other molecules.

(First published in: Kovar, et al. (2007) Anal. Biochem (In Press).)

Uses:

In vitro cell-based assays:
Dye-labeled targeting agents can be used in cell-based assays to evaluate binding of the labeled compound.  This technique is especially useful for testing and validation of optical agents that are ultimately intended for in vivo administration.  IRDye 800CW carboxylate can be used to evaluate specificity by testing for binding or other effects of the dye itself, in the absence of the targeting moiety. 

In vivo imaging:
When administering an optical agent in vivo, it is important to understand the behavior and clearance of not only the dye-labeled imaging agent, but also the dye itself in the absence of the targeting moiety.  IRDye 800CW carboxylate is the appropriate control for determining two important imaging parameters: the timing of dye clearance from the animal’s body; and specific organs or locations in the body where the dye itself may be retained for a longer period (for example, the liver or kidneys).  This information allows the researcher to more accurately interpret the results of imaging experiments.

Labeling Reaction Reference
When labeling proteins or other molecules with IRDye 800CW NHS ester reactive dye, unreacted or “free” dye is removed by purification after the labeling reaction is complete. Excessive amounts of unreacted dye that persist after purification can interfere with spectrophotometric determination of a dye/protein (D/P) ratio, and result in artificially high calculated D/P values. "Free" dye may also cause increased background fluorescence in subsequent biological assays. For these reasons, it may be useful to determine the amount of unreacted dye that remains after purification. 

Ordering Information: