AviTag™ Technology — Protein Biotinylation Tag for Purification, Immobilization or Sensitive Protein Detection


The AviTag™ is a popular fusion tag due to its powerful and versatile properties. Fused to your protein, the AviTag™ provides a multi-functional system useful for many applications including:

  • Expression
  • Imaging
  • Detection
  • Localization
  • Isolation
  • Immobilization


The AviTag™ technology is based on the biotinylation of AviTag™ by biotin ligase in vitro or in vivo and on the specific and reversible binding of avidin or streptavidin to biotin for immobilizing, purifying and visualizing proteins. See applications of AviTag technology.

Combined with OmicsLink™ expression-ready clones

GeneCopoeia offers the AviTag™ technology in a wide range of expression vectors. For example, it has been combined with the IRES (Internal Ribosome Entry Site) element and the SUMO, 6xHIS and a variety of other tags.See the complete list of AviTag expression vectors here.

The AviTag with T7- or CMV-driven promoters is available for more than 20,000 human and 15,000 mouse genes.

AviTag ORF cDNA clones



Biotinylation of recombinant protein bearing the AviTag is highly specific. In the presence of biotin and ATP, biotin ligase catalyzes amide linkage between the biotin and the specific lysine of the 15-aa AviTag peptide.

Biotinylated proteins in nature are extremely rare making the chances for cross reactions, especially when compared to antibodies, very low.

GeneCopoeia also offers biotin ligase, biotinylation strains and Avitag vectors.

Learn more about biotin ligase and biotinylation strains.


AviTag ORF cDNA clones

Figure1. OmicsLink ORF cDNA expression clones with N- and C-terminus AviTag in various mammalian vector systems.

Advantages over chemical biotin-labeling

  • During chemical biotin-labeling the protein can become inactivated due to random biotinylation of the protein surface by the attachment of biotin to protein catalytic or binding domains. With Avi-Tag, virtually any protein can be easily and efficiently biotinylated in vivo or in vitro using the single, unique AviTag site.
  • Biotinylation using Avi-Tag is performed enzymatically resulting in gentle reaction conditions and highly specific labeling.
  • Biotin-AviTag has 15 amino acids, which is a fifth of the bulk of alternative biotinylation tag sequences that are over 85 amino acid residues long; an important consideration if steric conflicts are to be minimized.

How it works

AviTag ORF clone to biotinylated protein