Store at -20°C; Desiccate; Avoid frequent thaw and freeze.

addition of a slight excess of (MeCN)4CuBF4 quantitatively formed an isolable octyne–Cu complex that is unreactive towards free azides. The Cu–alkyne complex could be disrupted by the addition of aqueous ammonia, regenerating the cyclooctyne and making it available for strain-promoted azide–alkyne cycloaddition.

To prevent decomposition of m -PEG DBCO Store it at -20°C in the desiccator.