ChromoTek - Home of the alpaca antibodies

NEW Spot-Cap™: novel affinity resin for Spot-Tagged proteins. Can be regenerated >5 times.

About ChromoTek

ChromoTek offers innovative research reagents based on camelid antibodies, which are devoid of light chains and have a single antigen recognizing domain. In the absence of light chains, the fragment-antigen-binding (fab) part of these antibodies is reduced to a single domain, the so-called VHH (variable domain of heavy chain antibodies) domain or nanobody. This single domain contains a complete antigen binding site and is the smallest functional antigen binding fragment (around 15 kDa, only one tenth the size of a conventional antibody).

The alpaca antibody advantage

ChromoTek’s Nano-Traps are perfect tools for the rapid immuno- precipitation of proteins and their interaction partners with high specificity and efficiency. Their Nano-Boosters enhance the signal intensity of your targets in fluorescent microscopy. And their Chromobodies® allow you to analyze endogenous proteins in living cells in real time. In addition , their new fluorescent 2-hybrid (F2H®) assay enables you to monitor reversible protein-protein interactions in a cellular system. Last but not least, their Spot-System is the first peptide-tag specific nanobody for universal capture and detec-tion applications. And now, ChromoTek offers Spot-CapTM,  a Nanobody-based affinity resin optimized for one step protein purification of Spot-tagged proteins. Click here to read the Alpaca Antibody Advantage story

Product offering


Nano-Traps are ideal for fast, reliable and efficient one-step immunoprecipitations. They pull down your proteins of interest (POI) and their interacting factors from cell extracts or organelles. Nano-Traps consist of a VHH, also termed nanobody, coupled to an immobilizing matrix. You can use Nano-Traps for a multitude of biochemical analyses such as:

  • Immunoprecipitation (IP) / Co-IP
  • Mass spectrometry
  • Enzyme activity measurements
  • ChIP / RIP analysis

Nano-Boosters and Nano-Labels

ChromoTek's Nano-Boosters/Labels are very small, highly specific binding proteins. They are derived from single-domain alpaca antibody fragments termed VHHs or nanobodies which are covalently coupled to bright and stable fluorescent dyes. As these nanobodies are much smaller compared to conventional primary plus secondary antibodies (IgG complex), they are particularly suitable for effective labelling with minimal fluorophore displacement for super-resolution microscopy. 

While Nano-Boosters, e.g. GFP- and RFP-Booster, enhance the signal of fluorescent proteins, Nano-Labels, e.g. Vimentin-, Histone- and Spot-Label, fluorescently label proteins.


  • Higher image resolution
  • Excellent performance in IF and super-resolution microscopy
  • Stabilization, enhancement and reactivation of fluorescent signals
  • Less than 2nm epitope-label displacement minimizes linkage error
  • Monovalent, recombinant single domain antibody fragment from camelid


Nano-Secondaries are secondary alpaca antibodies for higher resolution and better imaging, which are conjugated to Alexa Fluor® dyes. They can be used for Immunofluorescence, Super-resolution microscopy (SRM), Western blot and ELISA. As Nano-Secondaries are recombinantly produced, they are fully sequenced by design, which in combination with high QC standards ensures reliable and stable products virtually without batch-to-batch variation.

Why should you use Nano-Secondaries?

  • Thoroughly validated for precise and reproducible staining
  • Cross reactivity against multiple species’ antibodies and sera has been carefully determined
  • Economical: only small amounts needed

Higher resolution

Faster staining

Cleaner images


Product overview

Product name
Alexa Fluor®
Alexa Fluor®
Alexa Fluor®
Alpaca anti-rabbit, IgG recombinant VHH
10 ul
100 ul
Alpaca anti-mouse IgG1, Fc-specific recombinant VHH
10 ul
100 ul
August 2019
August 2019
Alpaca anti-mouse IgG2b, Fc-specific recombinant VHH
10 ul
100 ul
August 2019
August 2019
Alpaca anti-mouse IgG3 , Fab-specific recombinant VHH
10 ul
100 ul
August 2019
August 2019



ChromoTek's Chromobodies® are a novel species of extremely small intracellular functional antibodies. Chromobodies® are based on the antigen binding domain (VHH) derived from heavy chain antibodies of camelids genetically fused to a fluorescent protein (e.g.TagGFP or TagRFP from Evrogen). As opposed to conventional antibodies, these innovative fluorescent nanoprobes are suitable for real time analyses and can visualize endogenous cellular structures and processes in live cells.

In addition to stable cell lines, you can also obtain a Chromobody® plasmid, which allows you to create your own cell lines or transiently express a Chromobody®.

All Chromobody® binding domains are carefully selected to not interfere with endogenous protein function and offer the unique possibility to trace native proteins in living cells.

Spot-Tag®, Spot-Trap® and Spot-Cap

The ChromoTek Spot-System is the first peptide-tag specific nanobody for universal capture and detection applications. It comprises Spot-Tag®, an inert 12 amino acid peptide-tag (PDRVRAVSHWSS), Spot-Trap®, the universal, rugged Spot-nanobody that specifically binds to Spot-tagged proteins with high affinity, and Spot-CapTM, the new and optimized nanobody-based affinity resin.

Image on the right: interaction of Spot-Trap® nanobody (green) with Spot peptide.

Spot-CapTM advantages

  • Tight and selective binding to Spot-Tag® (PDRVRAVSHWSS)
  • Optimized for fast and gentle one-step purification at 4°C
  • High binding capacity and multiple regeneration cycles
  • Cost efficient compared to other affinity resins
  • Minimal contamination of host cell proteins

Spot-CapTM brochure

Spot-Tag® advantages

  • More robust & stable
  • Higher affinity
  • Less background
  • Less unspecific binding
  • Higher resolution

Spot-Trap® advantages

  • Less negatively charged
  • Short
  • Inert

ChromoTek's Spot-System can also be applied for CRISPR'ed Spot-Tags (see Brochures section for an application note).

In addition, ChromoTek provides a growing number of exceptionally specific conventional antibodies.