Spot Nanobody

Introduction and binding mechanism

The Spot Nanobody, also termed Spot VHH, is derived from single-domain alpaca antibody fragments. The Spot Nanobody recognizes the Spot-Tag® sequence motif PDRVRAVSHWSS. Binding occurs when the Spot-Tag peptide is embedded on the surface of the Spot Nanobody and acts like a β-sheet extension of the Spot-VHH. Specificity is determined by interactions of the Spot-Nanobody’s side chains to the Spot-Tag peptide. Notably, the bound Spot-peptide is also clamped by two amino acid side chains of the Spot-Nanobody. This binding mechanism explains the high affinity of the Spot-Nanobody.

The Spot Nanobody for

  • immunoprecipitation  is coupled to beads: Spot-Trap® 
  • protein purification is coupled to agarose: Spot-Cap®
  • immunofluorescence and Western blotting is coupled to fluorescent dyes: Spot-Label®
  • immobilization and coupling via NHS Ester reaction: Spot VHH

Spot-Nanobody is fully validated

  • Recombinantly produced for constant high quality
  • Sequence known
  • Structure determined
  • Binding mechanism understood

Features and benefits of the Spot Nanobody

Spot-Nanobody is better performing in many capture and detection applications than other antibodies. Most of these antibodies are conventional IgGs, which may suffer from stability and size. Spot-Nanobody however is small size to better access the Spot-Tag epitope. In addition, Spot-Nanobody is very stable and binds to Spot-Tag even under harsh conditions. Non-IgG type affinity reagents for affinity-tags can’t be used for detection and imaging of tagged proteins, whereas Spot-Nanobody has an outstanding performance in immunofluorescence and Western blotting. Spot-Nanobody is the first Nanobody/ peptide-tag that was applied in super-resolution microscopy.

Key Features

Key Benefits

  • Small size of just 14.7 kDa or 2 nm
  • High affinity binding of Spot-Tag with KD = 0.7 nM
  • High chemical and thermal stability
    with Tm = 65.1°C
  • No contaminating heavy & light antibody chains
  • Native elution with Spot-peptide & by pH shift
  • Matrix can be regenerated
  • Well characterized
  • Optimized Nanobody for gentle elution at 4°C
  • Specific binding with low background
  • Robust handling and stable in harsh conditions
  • Native & non-native elution
  • Highly specific binding
  • Higher resolution
  • Good epitope access & sample penetration
  • Good detection limits
  • Validated
  • Effective purification of Spot-tagged proteins






Free samples available

Request free sample here and test Spot in your experiment.