The 3xFLAG system is an improvement upon the original system by fusing 3 tandem FLAG epitopes (22 amino acids). Detection of fusion proteins containing 3xFLAG is enhanced up to 200 times more than other systems. Like the original FLAG tag, 3xFLAG is hydrophilic, contains an EK cleavage site, and is relatively small. Therefore, the risk of altering protein function, blocking other epitopes or decreasing solubility is minimized.
3xFLAG tagged genes are based on end-sequenced fosmid clones, not cDNA. Each tagged clone carries the complete gene of interest embedded in approximately 40 kb of native human or mouse genomic DNA, with the reporter sequence (3xFLAG tag) fused to the extreme 3?-end of the protein-coding sequence.
Glycerol stock of the highest quality FOSMID construct for downstream transfection and immuno precipitation using the 3X FLAG epitope system. Tagged genes are provided in fosmid vectors, each of which carries ~40 kb of genomic DNA. C-terminal tags are inserted at the 3′-end of the coding sequence of the gene of interest. Tagged genes may be delivered to cells using standard transfection protocols. Transfection frequencies generally range between 2% and 10%. Stable transfectants may be isolated by G418 selection for those clones that carry a neomycin resistance gene in the vector backbone.