Purification & Detection


The Most Sensitive Epitope Tag Expression System

  • Up to 200 Times More Sensitive
  • Extensive Selection of p3xFLAG™ Mammalian Vectors
  • Enterokinase Cleavable Tag

Low-level expression of recombinant proteins in mammalian cells is a common problem that often makes detection of epitope tags difficult or impossible. Detection of 3xFLAG using the ANTI-FLAG® M2 Ab and anti-mouse-HRP is 20-200 times more sensitive than any commonly used tag. An extensive selection of p3xFLAG vectors utilizes the strong CMV promoter to drive expression. In short, the 3xFLAG system ensures detection where other tags fail.

Features & Benefits

  • 20-200 times more sensitive than other tags for improved detection in Western Blots, IPs and Immunocytochemistry
  • p3xFLAG CMV vectors provide choice of N-terminal or C-terminal, intracellular or secreted expression, and stable or transient transfection expression of 3xFLAG tagged proteins.
  • 3xFLAG tag can be removed with enterokinase.


10-20 times more sensitive than FLAG

Up to 200 times more sensitive than any other tag


Western blot of purified 3xFLAG bacterial alkaline phosphatase and FLAG bacterial alkaline phosphatase transferred on to nitrocellulose membrane. Detection was performed with ANTI-FLAG M2 monoclonal antibody as primary, anti-mouse-HRP seconday antibody, and ECL™ chemiluminescent substrate.

3xFLAG vs Competitors

C-terminal fusions of GST and the tags listed above were prepared and analyzed on Western Blots. All proteins were detected using the appropriate tag antibodies, anti-mouse HRP and ECL.

For 3XFLAG fusion protein purification tools, click here.

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