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What Are Epitope Tags?

Epitope tagging involves fusing a well characterized epitope, typically a protein, peptide or small molecule, to the N- or C-terminal ends of a protein either by genetic engineering or chemical conjugation. Epitope tags, also known as affinity or fusion tags, function as universal epitopes. By using antibodies or other binding agents that recognize the tag, researchers can easily detect and identify proteins that lack specific antibodies, such as newly discovered proteins and proteins with low immunogenicity. Epitope tags are useful tools for several immunoassays including western blot, immunoprecipitation, and immunofluorescence. Additionally, they can be used with affinity chromatography to purify target proteins from complex samples.

Bio-Techne’s Alex Fluor® 488-Conjugated Anti-c-Myc Antibody is validated for immunocytochemical detection of c-Myc-tagged proteins in cultured cells.
Detection of a c-Myc-tagged Serotonin Receptor.

Benefits of Using Epitope Tags

  • Epitope tags can accelerate experiments as epitope tagging and the subsequent detection of the tag with commercially available epitope tag antibodies is quicker than producing new, antigen-specific antibodies.
  • Epitope tagging is also cheaper than producing new, antigen-specific antibodies.
  • Epitope tags can detect and affinity purify proteins that may be difficult to isolate and purify with other methods.
  • The same epitope tag can be used for different sized proteins and don’t compromise the native structure or function of the protein.

Types of Epitope Tags

There are many different epitope tags available, and the choice of tag is dependent on several factors, including the technique used to analyze the tagged protein. For example, fluorescent peptides, such as Green Fluorescent Protein (GFP), Allophycocyanin (APC), and Fluorescein Isothiocyanate (FITC) are used for cellular tracking and localization experiments while tags such as His, V5 and Glutathione S-Transferase (GST) are used in protein purification. Other epitope tags, such as DYKDDDDK (Flag®), c-Myc, and Hemagluttinin (HA)  are used for immunoprecipitation and to monitor protein-protein interactions.

Bio-Techne’s His Tag Antibody is validated for detection of His-tagged proteins by flow cytometry and western blot.
Detection of His-tagged SARS-CoV-2 Spike 1 protein.

Explore all the highly specific antibodies we offer for the epitope tags listed below. We offer several different conjugate options. Additionally, many of our epitope tag antibodies are available in both sample sizes and bulk quantities.


Avi Tag

c-Myc Tag

Digoxigenin Tag

DYKDDDDK Epitope Tag




HA Tag

His Tag

V5 Epitope Tag


Additional Resources

View of the Flow cytometry handbook and a single cell as a background

Flow Cytometry Handbook

This easy-to-follow guide provides an overview of the flow cytometry technique, as well as step-by-step protocols and troubleshooting tips.

ICC Handbook Cover

Immunocytochemistry (ICC) Handbook

Visit Novus Biologicals to download this comprehensive ICC guide. This handbook provides an introduction to the techniques, detailed protocols, and troubleshooting methods for the execution of successful multicolor ICC/IF experiments.