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SARS-CoV-2

Abcalis® anti-SARS-CoV-2 antibodies are high quality recombinant monoclonal primary antibodies

Abcalis’ product portfolio now also features anti-SARS-CoV-2 recombinant (sequence defined) monoclonal antibodies. We believe that recombinant primary antibodies can deliver a significant improvement over the current standard testing procedure of utilizing RT-PCR testing. Given that RT-PCR tests are complex, cost-intensive and time-consuming, the tests are not truly suitable for the real-time control of epidemiological measures due to the time delay from taking the sample until getting a result, which also makes them unsuitable for mass market real-time diagnostics for point-of-care (POC) testing (e.g. medical practices, hospitals, etc.).

Hence Abcalis’ approach for recombinant primary antibodies to be used in antigen based rapid tests. See below how we select and validate our anti-SARS-CoV-2 antibodies:

Regarding antigen based tests, apart from other factors these tests are also partially based on the use of an antibody validated for binding to heat-inactivated virus particles. But the assumption that antibody binding against heat-inactivated virus particles is similar to binding to the native viral protein may underestimate the risk of false positive results.
The solutions from and with Abcalis are therefore qualified to meet regulatory standards and criteria even in the long term, as is the standard with all Abcalis products, since they are all completely sequence defined, implying their unlimited long-term availability and always identical test results. This allows for a much lower unspecific binding reactivity in many assays compared to animal based products.

Multiclonals

Abcalis® Multiclonals are a revolutionary new class of secondary antibodies

Abcalis® believes that the future of secondary antibodies is recombinant, sequence defined and animal free. In therapeutics, recombinant antibodies have long been the gold standard for real-world application and we do not see any reason why this should be different for diagnostics and research. Multiclonals combine the best of polyclonal antisera and hybridoma monoclonal antibodies, while eliminating their disadvantages, plus they add the quality of recombinant reagents.
Our Multiclonal antibodies are a mixture of different, carefully selected recombinant monoclonal immunglobulins. Their respective epitope binding sites do not compete with each other, therefore amplifying signal strength in each and every one of your test results.

As is the standard with all Abcalis® products, they are all completely sequence defined, implying their unlimited long-term availability and always identical test results. Their composition of individually characterised antibodies minimizes cross-reactivity with other targets, since they do not contain non-target directed IgG like all animal derived polyclonals do. This allows for a much lower unspecific binding reactivity in many assays compared to animal based products – see data of a direct comparison below.

This is how we make multiclonal antibodies without the need for animal immunisation or the use of other animal materials (except some milk powder for blocking):

Abcalis® Multiclonals can contain up to 17 different individually tested monoclonal recombinant antibodies. This provides the typical advantage of polyepitope recognition which is key to the broad application profile of polyclonal antisera, but eliminates their disadvantages (limited batch sizes and batch-to-batch variations, no long-term reproducibility, undefined composition, unknown constituents) and allow to minimize your QC. Hence, you are receiving all the advantages of conventional polyclonal mixtures, but without their downsides.

More specificities and labels are in the making!

Multiclonals combine the best of polyclonal, monoclonal and recombinant antibodies

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Abcalis® Multiclonal Anti human IgG(Fc) secondary antibodies show lower cross-reactivity

Abcalis anti human Immunoglobulin multiclonals consist of carefully adjusted mixtures recognizing different epitopes on all four different subclasses of human IgG:

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Direct comparison of Abcalis multiclonals with typical animal-derived products revealed a much lower cross-reactivity binding of the recombinant product in some applications. Example:

Quantitative capillary western blots

Simple Western Immunoassay* is an automated gel-free and blot–free method to provide quantitative immunoblot results. An antigen target was separated by capillary electrophoresis according to its size, then identified by antigen specific primary human IgG. Either Abcalis® MULTICLONAL or animal derived secondary antibody anti-human IgG HRP were used to detect and visualize the reaction with a chemiluminescent substrate. The resulting chemiluminescent signal allows quantification over a broad range of concentrations.

*Simple Western Immunoassay™ and Protein Simple™ are trademarks of ProteinSimple, San Jose, USA

Monoclonals

Monoclonal antibodies with sequence-defined composition

All ABCALIS® Antibodies are made in vitro by animal-free recombinant methods (phage display).

All our antibodies are of completely defined composition, as the encoding DNA sequence of all components in known. This assures always identical results, unlimited long-term availability and therefore true reproducibility.

All antibody products are recombinantly produced in animal-serum free media by human HEK293 cell culture and purified from the supernatant by Protein A affinity chromatography.

All prices are in Euro and are given without german VAT (Umsatzsteuer).

For a more sustainable future.
And higher quality of your results.

We envision a world of next generation diagnostic antibodies that share a revolutionary level of quality and are completely animal-free.

The immunization of animals and the extraction of animal sera is a practice that was initially conceived by Emil von Behring in the year 1890 and has been around ever since.
However, new technologies today allow to generate antibodies without the use of immunized animals. The Nobel Prize honoured technology of Antibody Phage Display allows to select antibodies entirely in vitro.

By using our sequence defined recombinant antibodies, you can obtain superior quality of your results with animal-free reagents.
It is our mission and aspiration every single day to achieve this goal, both for a sustainable future and medical safety of this and every future generation to come.

So why go recombinant?

Reproducibility.

Scientific progress as well as life-saving diagnostic decisions are based on assays built on the fundamental principle of reproducibility of experimental results.
A second essential requirement is utmost capability to discriminate true from false-positive and false-negative results.

Despite all care we built into our sophisticated biological, biochemical or immunological assays, today we still depend on one component which is neither available in unlimited amounts to provide reproducibility, nor is it defined well enough to assure minimal false-positive and false-negative results.

These are animal derived serum products, typically used as first and/or secondary antibodies.

In a PCR-based assay, would you use a primer set without knowing the exact sequence of these primers and without the possibility to sequence the generated PCR amplicon for confirmation?
Nowadays, when using antibodies for detection of a specific protein, we have to do exactly that, since typical diagnostic or research antibodies are not defined by their sequence, often contain many undefined additional components and other IgGs present in the animal which produced them, and vary in their composition over time¹.

Most antibodies used for research and diagnostics today are still polyclonal serum products obtained after animal immunization – mainly due to the low prices. On the other hand, this animal origin is responsible for significant batch to batch variations and product discontinuity.

Specificity.

Also, animal derived antisera always contain many other Immunglobulins of unknown specificity, causing an intrinsic risk of exhibiting unwanted reactivities which can never be completely excluded by affinity purification steps^2-7.

While also still depending on animal immunization, the hybridoma technology substantially improved this scenario, as it allowed the production of monoclonal antibodies for the first time.
Yet, contrary to widespread belief, these antibodies are not always monospecific. As shown in a multicentric study⁸ of 185 monoclonal hybridoma sequences, a striking 30 % of these hybridomas expressed additional productive light chains, sometimes even additional heavy chains, resulting in the generation of an oligospecific mixture of antibodies in their supernatant.

So, monoclonals are not as defined as we thought. Furthermore, hybridoma antibodies do not provide the epitope diversity of polyclonals, which can result in lower signals and a more narrow application profile. Finally, storage of hybridoma lines in liquid nitrogen constitutes a quite expensive and not flawless system, that already caused the loss of countless hybridoma clones, making a future reproduction of results with these antibodies impossible.

As a result, the only unequivocally monoclonal antibodies are sequence defined antibodies generated and produced with recombinant technologies, typically antibody phage display. Only these antibodies provide infinite reproducibility, since they can always be reconstituted from their electronically stored or printed amino acid sequence.

In conclusion.

The creation of MULTICLONALS⁹, target specific and multi-epitope binding defined mix of sequence defined recombinant antibodies, allows to combine the benefits of polyclonal antibodies with monoclonals plus while adding the benefits of sequence defined reagents.

Add-on utility of the recombinant format: choose to fit your detection system.

Since the DNA encoding Abcalis® antibodies is always available from the start, we can fuse the antigen binding end to many other protein domains. Typically, Fc from other species than human can be used, to combine e.g. three different Abcalis® antibodies in a three colour staining, using three different secondary antibodies. An example of a triple colour immunfluorescence application is given by:

Moutel et al. (2009). A multi-Fc-species system for recombinant antibody production. BMC Biotechnology 9:14

Versatile recombinant format: “choose your species”! ScFv-Fragments from human libraries can be detected by anti-mouse Fc, anti-rabbit Fc or other secondary antibodies if they have been fused accordingly. While we may not always have every possible combination on stock, we do produce respective versions on request – or even fuse other Fc parts or detection domains you may need for your particular experiment. Just contact us and ask for a quote.

Bradbury A, Plückthun A. (2015). Getting to reproducible antibodies: the rationale for sequenced recombinant characterized reagents. Protein Eng Des Sel. 28(10):303–305.
Berglund L et al. (2008). A genecentric Human Protein Atlas for expression profiles based on antibodies. Mol Cell Proteomics 7(10):2019-2027.
Bradbury A, Plückthun A. (2015). Reproducibility: Standardize antibodies used in research. Nature 518(7537):27-29.
Dove A. (2017). Technology Feature | Agreeable antibodies: Antibody validation challenges and solutions. Science 357(6356):1165-1167.
Goodman, 2018. The antibody horror show: an introductory guide for the perplexed. New Biotechnol 45:9-13.
Bradbury A, Plückthun A. (2015). Antibodies: Validate recombinants once. Nature 520(7547):295.
Taussig MJ et al. (2018). Antibody validation: a view from the mountains. N Biotechnol 45:1-8.
Bradbury et al. (2018). When monoclonal antibodies are not monospecific: Hybridomas frequently express additional functional variable regions. MAbs 10(4):539-546.
https://www.abcalis.com/multiclonals

We are Abcalis® and we specialize in a new class of recombinant secondary antibodies for diagnostics.

Antibodies are a vital component in medical diagnostic tests. Especially secondary antibodies are used in a wide variety of immunodiagnostic assays and testing kits to either prove or disprove the presence of pathogenic antigens in patients.

Theres is just one problem: Today’s secondary antibodies are either polyclonal mixtures taken and purified directly from animal sera or monoclonal antibodies derived from hybridomas, both of which are of animal origin.

This generates a multitude of challenges:

Animals are used for immunization and blood extraction through which they eventually die
A stark fluctuation of quality due to different animal sera and individually occurring impurities
Since every animal provides a unique composition of antibodies, the consequences are limited availability and no product continuity

Abcalis® solves this with a new and unique brand of secondary antibodies: Multiclonals.

Read more below as to why our products mark true progress in the field and hence are a true innovation for antibody applications.

Abcalis® MULTICLONALS combine the best of two worlds.

All Abcalis® Multiclonals are produced recombinantly and can therefore benefit from the established advantages of polyclonal mixtures, while eliminating the downsides regarding long-term availability and reproducibility, antigen purification and lack of continuous product identity.

Our antibodies are selected by 2018 Nobel-Prize Winning technology Antibody Phage Display in vitro. Our process is based on know-how and libraries developed by one of its inventors, building on the experience of >25 years.

No animals are used for their production.

Check our Animal Use Statement as well as the Tech Notes about our brand new MULTICLONALS and Hyper-Myc antibodies below.

Product Literature

MULTICLONALS TECH NOTE

A revolutionary class of antibodies for diagnostics

Defined compositions with high affinity and specificity.
Highly purified by Protein A affinity chromatography.

Scalable batches and adjustable Fc-parts

Practically unlimited supply and batch sizes.
Choose the Fc-part (mouse, rabbit, human) that is best for your setup.

Sequence defined

Reproducible results forever.
Further improvement possible on request.

Animal free

No more batch-to-batch variation due to different sources.
Continuously high quality levels. Quality assurance simplified.

Check out below why our antibodies are different from animal-derived monoclonal antibodies from hybridomas.

A recent international multicentric sequencing study showed that about one third of 185 sequenced hybridoma cell lines secreted mixtures of different IgGs with at least three different antigen binding sites, thus compromising both specificity and binding strength. Original paper:

Bradbury, A.R.M. et al. (2018) When monoclonal antibodies are not monospecific: hybridomas frequently express additional functional variable regions. mAbs, 10, 539-546
Free download of this paper