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Spot-Tag & Applications

Affinity Optimized Short Peptide Tag

The Spot-Tag® has the affinity-optimized 12 amino acid sequence PDRVRAVSHWSS. Spot-Nanobodies bind strongly to the Spot-Tag. The inert tag sequence can be added to the N-terminal and to the C-terminal side of the protein of interest. This works by PCR using modified primers or by using any of the Spot vectors offered (click here for more information). The expression of Spot-tagged proteins has been successfully tested in bacteria, yeast, mammalian cell lines, plant and insect cells.

Spot-Nanobody advantages
compared to other antibodies:

Spot-Tag advantages
compared to other peptide tags:

  • More robust & stable than IgG antibodies
  • High affinity of 6 nM to Spot-tagged proteins and 0.7 nM to Spot-Tag
  • Less background than other tested affinity resins
  • Less unspecific binding than other tested capture and detection antibodies
  • Higher resolution than conventional antibodies
  • Better epitope accessibility and tissue penetration than conventional IgG antibodies
  • Effective and gentle elution at 4°C (Spot-Cap)
  • Less negatively charged than
    FLAG®-, Myc-, and HA-tags
  • Short
  • Inert, unstructured tag does not interference with fusion protein structure and function
  • Binding of a single tag 
  • Suitable for ubiquitination assays: comprises no lysine


Overview of Spot related products by application

Immunoprecipitation (IP): use Spot-Trap

Spot-Trap® is the Spot-Nanobody coupled to agarose or magnetic agarose beads.

  • NO contaminating heavy & light antibody chains
  • Harsh washing conditions
  • Native & non-native elution
  • High affinity, stringent wash

Protein purification: use Spot-Cap

Spot-Cap®  is an optimized Spot-Nanobody derivative coupled to agarose beads for purification of Spot-tagged proteins.

  • One step protein purification
  • High binding capacity
  • Multiple regeneration cycles
  • Effective elution at 4°C with Spot-peptide or pH shift

Immunofluorescence (IF): use Spot-Label

Spot-Label®  is the Spot-Nanobody conjugated to fluorescent dyes. The bivalent Spot-Label is the first Nanobody/ peptide-tag that was applied in super-resolution microscopy.

  • Higher resolution
  • Better epitope access & tissue penetration
  • Very small probe size

Expression of Spot-tagged fusion proteins: use Spot-Tag vectors

A selection of Spot-Tag vectors is available. Alternatively, Spot-Tag can be easily cloned by PCR primers.

Elution of bound Spot-tagged protein: use Spot peptide

Spot peptide for gentle elution of Spot-tagged proteins from Spot-Cap™.

Western Blotting, ELISA: use Spot-tag antibody [28a5]

Spot-tag® antibody [28A5], mouse monoclonal:

  • Very sensitive in Western blot and ELISA

For more information about the Spot-Tag and Spot Nanobody see

Free samples available

Request free sample here and test Spot in your experiment.