Cy3 maleimide (non-sulfonated)

Cy3 maleimide is a selective and efficient fluorophore dye with low aqueous solubility. This labeling reagent can be used to attach Cy3 fluorophore to proteins and peptides which contain cysteine residues, as well as to other thiolate molecules (such as thiol-containing oligonucleotides). Before the labeling reactions, Cystines should be reduced with TCEP (tris-carboxyethylphosphine). 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.

MSNs were labeled by Cy3 maleimide named MSN-Cy3s at the concentration of 10 μg ml-1. MSN-Cy3s incubated with MEF-mEGFP cells on a glass coverslip in culture medium for 2 h To further visualize the MSN locations in the cytosol we used super-resolution microscopy (3D SIM). The visually microscope image results confirm that MSNs were internalized by MEF-mEGFP cells [1].

Reference:
[1].  Chiu, H.-Y.; Deng, W.; Engelke, H.; Helma, J.; Leonhardt, H.; Bein, T. Intracellular chromobody delivery by mesoporous silica nanoparticles for antigen targeting and visualization in real time. Scientific Reports, 2016, 6, 25019.