Smart Secondaries™

Exploit the full potential of your primary antibodies!

A set of single-domain antibodies recognizing conventional immunoglobulins with exquisite species and isotype specificity is the core of our patented technology.
Our secondary tools provide unique benefits for all antibody-based assays in research and diagnostics by combining reproducible specificity and production with small and high-affinity monovalent binding.
In addition, our technology offers surprising new possibilities like one-step indirect immunofluorescence or easy multiplexing.


Here you find all our Smart Secondaries™

Discover the advantages of Smart Secondaries™

NanoTag developed a unique set of high-affinity single-domain antibodies recognizing conventional immunoglobulins with exquisite species and isotype specificity. These tools are available directly coupled to fluorophores, biomolecules, and enzymes. Our Smart Secondaries™ can therefore fully replace conventional secondary reagents in most applications. In comparison to conventional secondary reagents, our Smart Secondary™ nanobodies feature significant advantages:

  1. Small probes for enhanced staining speed and improved tissue penetration and higher resolution.
  2. Monoclonal tools: Clearly defined species specificity – once and forever!
  3. Isotype specificity for independent detection of mouse IgG1 and IgG2a/b isotypes.
  4. FluoTags® featuring a defined number of fluorophores at known positions
  5. Recombinant production for reliable qualityscalability and reproducibility without using animals
  6. Monovalent binding mode – Pre-incubation without clustering primary antibodies possible!
  7. Extraordinarily strong binding allows one-step multi-color stainings & imaging even with primary antibodies from identical species and isotype (Multiplexing)
  8. Equipped with NanoTag’s propriety FX technology for improved post-fixation and enhanced performance in demanding application (e.g., expansion microscopy, DNA-PAINT, dSTORM, etc).

Our Smart Secondary™ sdAb generally recognizes the Fc domain on the respective primary antibody (the only exception being the FluoTag®-X2 anti-Mouse Kappa light chain). Due to the inherent symmetry of the target antibody, two secondary nanobodies will be able to bind each primary antibody. Our secondary FluoTag®-X2 reagents will therefore target 4 fluorophores to each primary antibody. 

Our anti-Rabbit IgG tools are also available as FluoTag®-X4. This reagent is a blend of two sdAbs independently binding the same target molecule. As each target site is present twice and each sdAb carries two fluorophores, this reagent can target up to eight fluorophores to each primary antibody – ideal for bright images!

Here you find all our Smart Secondaries™


Celline
Rapid and efficient affinity selection of target-specific B lymphocytes

NanoTag’s proprietary technology called “Celline” allows for the straightforward discovery of single-domain antibodies by affinity purification of target-specific B lymphocytes from a pool of PBMCs.
Using a single selection step, Celline drastically speeds up sdAb candidate selection while at the same time allowing to set avidity/affinity boundaries.
This method has a proven record for the fast generation of high affinity and low-affinity binders.

The ALFA system
One tag – Three sdAbs – Unlimited applications

A unique, patented technology based on three single-domain antibodies recognizing a rationally designed epitope tag of only 14 amino acids.
Covering a range from pM to nM affinities, this highly specific sdAb ensemble allows for an unmatched spectrum of applications.
High-resolution imaging in life or fixed cells, immobilization and affinity purification of functional proteins and protein complexes, and even therapeutic applications – everything is possible!

Smart Secondaries™
Exploit the full potential of your primary antibodies!

A set of single-domain antibodies recognizing conventional immunoglobulins with exquisite species and isotype specificity is the core of our patented technology.
Our secondary tools provide unique benefits for all antibody-based assays in research and diagnostics by combining reproducible specificity and production with small and high-affinity monovalent binding.
In addition, our technology offers surprising new possibilities like one-step indirect immunofluorescence or easy multiplexing.

FluoTags®
Fully defined ready-to-go single-domain antibody conjugates

FluoTag® is NanoTag’s trademark for camelid single-domain antibodies conjugated to chemical fluorophores.
All FluoTags® carry a defined number of fluorophores at known positions. Accordingly, they are available as FluoTag®-Q (one fluorophore; Quantitative) or coupled to multiple fluorophores (FluoTag®-X2 or FluoTag®-X4).
Together with their monovalent binding mode, the defined fluorophore conjugation of FluoTags® results in a more quantitative and reliable readout in all fluorescence-based analyses.

FX technology
FX technology for reliable post-fixation and expansion microscopy

Our sdAbs can be equipped with fixation (FX) cassettes, short amino acid stretches featuring multiple primary amines.
FX cassettes significantly improve the post-fixation properties of sdAbs, which is beneficial for extended experimental procedures, e.g. STORM and DNA-PAINT microscopy.
In addition, FX cassettes provide multiple anchor points in a ProteinaseK-resistant environment and therefore improve the retention of fluorophores in expansion microscopy (ExM) applications.

Selector resins
Affinity purification made easy!

Selector resins are affinity resins based on controlled immobilization of single-domain antibodies.
For production, high-quality agarose and magnetic-agarose resins are functionalized in-house using propriety chemistry. This results in both a highly specific, stable, and oriented sdAb attachment and an ultra-low non-specific background binding.
The precise and oriented chemistry also ensures optimal functionality and accessibility of the sdAbs and therefore results in beads with a high capacity.

Recombinant heavy-chain antibodies
Single-domain antibodies fused to immunoglobulin Fc domains

A fusion of a single-domain antibody to an immunoglobulin Fc domain results in a heavy-chain antibody. Such divalent recombinant antibodies provide maximal flexibility for technologies based on conventional Fc domains, like, e.g., classical secondary amplification systems.
HcAbs can, however, also be detected using our Secondary nanobodies.

One-step indirect immunofluorescence
One-step indirect immunofluorescence: Combine higher resolution with experimental speed!

Conventional secondary antibodies are multivalent and therefore form large clusters with primary antibodies.
In contrast, our species-specific secondary nanobodies are monovalent binders and therefore form defined stoichiometric complexes with primary antibodies in solution.
This feature efficiently prevents cluster formation. Primary antibodies and secondary nanobodies can therefore be pre-mixed or even co-incubated on the sample and thus enable convenient one-step immunofluorescence or Western assays.

Multiplexing
One-step multi-color detection breaking species boundaries

Due to their monovalent high-affinity binding, NanoTag’s species and isotype-specific secondary nanobodies allow multi-color fluorescent assays using multiple primary antibodies raised in the same species.
Multiplexing thereby drastically expands the possible combinations of primary antibodies and at the same time comes with extra features like a time-saving one-step protocol and an increased imaging resolution.
Discover the new freedom in all multi-color fluorescent assays!

Bi-specific sdAb fusions
Freely combine sdAbs to create new adaptor entities!

Bi-specific sdAb fusions (diabodies) are often used as adaptor molecules bringing two individual target molecules in tight contact.
A fusion of two sdAbs targeting the same molecule at different sites may also be used to increase the apparent binding affinity.
NanoTag has first-hand experience in the design, cloning, and expression of bi-specific sdAb fusions in prokaryotic- and eukaryotic systems and provides ready-to-to vector systems.

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