Identify the alkyne type
Check the structure or documentation of the target modification. Terminal alkynes require copper catalysis with an azide dye; strained alkynes such as DBCO support copper-free SPAAC. Two azide groups do not form this click pair.
Check sample and downstream assay compatibility
CuAAC copper, ligands and reducing components can affect the sample or downstream assay. Plan purification and retain a processing control without dye. SPAAC avoids copper, but target function after modification and free-dye removal still need checking.