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FLAG versus GST - (Jul/13/2005 )

FLAG and GST, any differences in pull-down assay?


Because almost all the paper I read used GST, I am not sure whether I can use a FLAG as well. ANy body can help me? Thanks in advance smile.gif


Hi bigeye,

The advantage of GST is in the matrix used in purification (glutathione agarose) and the fact that it can competed off the column and purified in what is considered a gentle way.

If you use FLAG (and you can) to obtain the protein you must immunoprecipitate with an anti-FLAG antibody coupled to Protein-A or -G. Consequently, Flag is handy for detection as the anti-FLAG antibodies are very good, but if you want to purify protein than GST is definately the way to go.

Hope this helps