Janelia Fluor 646 TFA (JF646 TFA), a red fluorogenic fluorescent dye, can be used in the synthesis of Janelia Fluor 646 HaloTag and SNAP-Tag ligands. JF646 TFA is used in live cell imaging experiments [1] [2]. Janelia Fluor fluorescent dyes can be chemically conjugated to the specific HaloTag substrate (a chloroalkane ligand) to form a fluorescent ligand, rather than binding directly to the HaloTag protein itself. Janelia Fluor products are licensed under U.S. Pat. Nos. 9,933,417, 10,018,624 and 10,161,932 and other patents from Howard Hughes Medical Institute (Ex/Em = 646/664 nm).
In Vitro, Janelia Fluor fluorescent dyes do not inherently possess HaloTag-binding activity; however, reactive groups serve as reaction sites for covalent coupling-via chemical synthesis-to an amino-functionalized HaloTag chloroalkane ligand scaffold, thereby yielding a fluorescent HaloTag ligand.
References:
[1]. Grimm JB, Muthusamy AK, Liang Y, et al. A general method to fine-tune fluorophores for live-cell and in vivo imaging. Nat Methods. 2017;14(10):987-994. doi:10.1038/nmeth.4403.
In Vitro, Janelia Fluor fluorescent dyes do not inherently possess HaloTag-binding activity; however, reactive groups serve as reaction sites for covalent coupling-via chemical synthesis-to an amino-functionalized HaloTag chloroalkane ligand scaffold, thereby yielding a fluorescent HaloTag ligand.
References:
[1]. Grimm JB, Muthusamy AK, Liang Y, et al. A general method to fine-tune fluorophores for live-cell and in vivo imaging. Nat Methods. 2017;14(10):987-994. doi:10.1038/nmeth.4403.