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.


With Celline, NanoTag introduced a unique proprietary technology for the time-efficient discovery of single-domain antibodies. 

In a single affinity selection step, a solid support displaying the target protein is used to purify target-specific B lymphocytes isolated from a pool of PBMCs. After washing, individual B-cells presenting target-specific antibodies on their surface are selectively eluted and further processed. The genetic information containing the sequence for the displayed antibodies is extracted, amplified by RT-PCR with sdAb-specific primers, and cloned into a prokaryotic expression vector. Identified sdAb clones are finally analyzed by ELISA or target-specific functional assays. Importantly, the washing stringency and elution mode during the initial affinity selection step can be customized within a wide range of conditions. This allows for the enrichment of B cells presenting antibodies with desired properties already in this stage. 

In terms of topology, Celline is an ideal camelid sdAb discovery platform when downstream assays and technologies require sdAbs to recognize proteins presented on the surface of target cells, e.g., surface-protein directed purification of blood cells or CAR-T technologies. Celline may therefore be advantageous especially for the selection of sdAbs intended for such applications. 

Celline is a single-step method and ideally suited for the time-efficient development of sdAbs. After immunization, single binders can be identified within 5-8 working days. 

NanoTag is currently implementing additional steps rendering the selection process specific to camelid B cells presenting camelid heavy-chain antibodies (IgG2/3 isotypes), which are the precursors of single-domain antibodies.


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 proprietary 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-use vector systems.

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