SYnAbs Rat-LOU Monoclonal Antibodies

When you perform intraperitoneal injection of hapten or highly homologous antigens in mouse species, most of the time your project is going to fail. Due to poor immunogenic properties and low molecular weight, your antigen is going to be eliminated in animal urine without generating any humoral immune response.


That's why we've created SynAbs in the first place, based upon an exclusive asset: the rat-LOU species and rat-LOU IR983 myeloma cell line, developed in 1983 by Hervé Bazin in Catholique University of Louvain-la-Neuve (UCL).


The custom generation of rat-LOU monoclonals is mastered by the SynAbs team since several years, as demonstrated by our 100+ references catalog and more than 1000+ fusions. The specific and proprietary rat developed and used by SynAbs, the Rat-LOU, is excellent for generating antibodies against small and poor immunogenic molecules including antibiotics, toxins, peptides, steroids, lipids, chemical entities, polysaccharides, highly conserved epitopes and transmembrane proteins.


The Rat-LOU also gives excellent results against murine antigens as surrogates and rat antibodies can be paired with existing antibodies in ELISA sandwich assays.


Last but not least, the generated antibodies are at least as stable and productive than the mouse ones, due to our proprietary rat IR983F fusion cell line, generating very stable fully rat-LOU hybridoma.

Benefits of rat-LOU monoclonal antibodies

High specificity and affinity monoclonal antibodies


Rat-LOU species gives the access to natural immune responses to obtain higher affinity monoclonals in secondary organs like lymph nodes and bone marrow. Contrary to display technologies, in-vivo maturation leads to the optimal combination of variable and constant domains resulting in :

Monoclonals with high specificity features,

Antibodies with effector functions for therapeutic purpose,

Monoclonal antibodies with great druggability features.

Excellent outcomes for small and poor immunogenic antigens


Rat-LOU species is a wild-type strain that exhibits a strong immune response when injected with foreign material. Its transgenic counterparts have so far shown a tendency to a low anti-serum titer. Rat-LOU generates immune responses against self-antigens, haptens, and highly homologous proteins. Consequently, SYnAbs uses it to generate monoclonals against small molecules, carbohydrates, lipids, epigenetic modifications but also complex transmembrane receptors.


Additional epitope recognition


The repertoire of the Rat-LOU allows the generation of unprecedented diversity of complementarity-determining regions (CDRs) on monoclonal antibodies, very different from other rodents.


Rat antibody Fc very close to human one


Rat-LOU gives you access to Fc competent monoclonal antibodies, potentially recruiting components of the immune system for ADCC and CDC responses. Furthermore, rat Fc is very similar to Fc of human immunoglobulin.


Rat antibodies are perfect for mouse antigens


Working with rat-LOU species allows you to check cross-reactivity of the generated monoclonals against different species to generate surrogates and therapeutics at the same time. Working on therapeutic projects, SYnAbs team screens your monoclonal against mouse, cynomolgus and human counterparts : our anti-CD2b is one of the outcomes of such approach.


Rat-LOU monoclonals in clinical trials


Rat-LOU monoclonals can be chimerized and humanized as easily as those of mice. Consequently, monoclonal antibodies derived from Rat-LOU have already been proven in clinical phases, the best known being LO-CD2a, MEDI-507 or Siplizumab, licensed to MedImmune/AstraZeneca. SYnAbs has also clinically proved the efficacy and safety of anti-CD25 LO-TACT.