Sulfo-Cy5 carboxylic acid is a non-activated, sulfonated, hydrophilic and highly water soluble dye. Non-Sulfo-Cy5 carboxylic acid analog is available. For kinds of researches related experiments, using pre-activated sulfo-Cy5 NHS ester is preferred. To labeling proteins and peptides, no organic co-solvent is needed. In life science, the sulfonate groups make the Cy dyes soluble in water and also reduce fluorescence-quenching which can arise from dye–dye interactions.
In the soma of SNc DA neurons, to examine whether cyamemazine accumulates in the soma of SNc DA neurons, ovoid neurons were patch clamped and filled with the Sulfo-Cy5 carboxylic acid. [1].
Reference:
[1] Tucker, K. R.; Block, E.R.; Levitan, E.S. Action potentials and amphetamine release antipsychotic drug from dopamine neuron synaptic VMAT vesicles. Proceedings of the National Academy of Sciences of the U.S.A., 2015, 112(32), E4485–E4494.