Cy7.5 NHS ester is a NIR dye with low aqueous solubility and long-wave emission. This labeling reagent is amine-reactive derivative of this fluorophore. In vivo, near infrared radiation can be used for imaging applications for it readily penetrates tissues. This product can be used for the labeling of various biomolecules such as proteins and peptides which contain amine groups, to track their distribution in organism in vivo. For biomolecule labeling, the labeling reagent has low aqueous solubility, using of organic co-solvent to dissolve this molecular is necessary for efficient reaction. First, Cyanine dye should be dissolved in organic solvent and then added to a solution of biomolecule in appropriate aqueous buffer.
In mice, Cy7.5 NHS ester labeled insulin (Cy7.5-INS) and were injected via subcutaneous injection at insulin dose of 1 IU/kg. The biodistribution of Cy7.5-Labeled insulin, INS/HTCC, and INS/HTCC-CA11 Nanoparticles was easily analyzed [1].
Reference:
[1] Zhang, Z. ; Cai, H.; Liu, Z.; Yao, P. Effective Enhancement of Hypoglycemic Effect of Insulin by Liver-targeted Nanoparticles Containing Cholic Acid-modified Chitosan Derivative. Molecular Pharmaceutics, 2016, 13(7), 2433-2442.