CF® dye picolyl azide reacts with alkyne to form 1,2,3-triazole by 1,3-dipolar Huisgen cycloaddition through the use of a much lower copper (I) concentration without sacrificing reaction efficiency. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. Far-red/near-IR fluorescent CF®770R dye has excitation/emission at 680/701 nm.