FcRn molecules


Exploiting FcRn mediated rescue has emerged as a generalizable approach to improving the pharmacokinetics of therapeutics. The ability to measure FcRn interactions is a prerequisite for the study and eventual manipulation of FcRn mediated rescue. Immunitrack offer FcRn from a variety of species (human, mouse, rat , pig, dog, guinea pig and cow) all are produced with the corresponding beta 2 microglobulin. For expression purposes unpaired cysteines are mutated to serines, this does not affect the ligand binding characteristics of the FcRn´s. The molecules are 100 % active and can be supplied with or without an enzymatically biotinylated C terminus.

Compatible platforms

The molecules have been tested successfully on a variety of platforms (AlphaScreen, Octet and Biacore), please see below. An application note on the Biacore platform was developed in a collaboration with GE healthcare, it can be downloaded here: FcRn Immunitrack GE collaboration

For quotes and order please download form and send it to us: Form for download   


New publication where, our human FcRn was used: Neonatal Fc Receptor Binding Tolerance toward the Covalent Conjugation of Payloads to Cysteine 34 of Human Albumin Variants


FcRn molecules

Immunitrack offers FcRn´s from a variety of species (human, mouse, rat , pig, dog, guinea pig and cow) all produced with the corresponding beta 2 microglobulin from the relevant species. For expression purposes unpaired cysteines have been mutated to serines, this does not affect the ligand binding characteristics of the FcRn´s. The molecules are 100% active and can be enzymatically biotinylated at the C terminus of the FcRn heavy chain, allowing IgG and albumin to bind simultaneously. The molecules have been used successfully on a wide range of assay platforms, please see below.


SDS-PAGE gel shift assays showing the biotinylation of FcRn heavy chains, the site specific biotinylation at the C terminus ensures directed immobilization and allows simultaneous binding of albumin and IgG.


Customer testimonial from Novozymes

Novozymes Biopharma uses the FcRn from Immunitrack to develop the albumin based half-life extension platform Veltis®. We have tested a number of commercially available FcRn’s in our screening assay developed for identification of albumin variants with improved affinity for FcRn receptor and found that the biotinylated FcRn’s from Immunitrack deliver superior performance. These biotinylated FcRn’s enable a robust immobilization to Streptavidin-biosensors (Octet Red96 from Pall ForteBio) and deliver very consistent and robust data.

Birgitte Andersen
Science manager


 Products and prices

product code b2m FcRn biotinylated size (ug) List price (euro) availability
ITF01-400 human human yes 400 1300 in stock
ITF01-1000 human human yes 1000 2600 in stock
ITF02-400 human human no 400 1100 in stock
ITF02-1000 human human no 1000 2200 in stock
ITF03-400 mouse human yes 400 1300 in stock
ITF03-1000 mouse human yes 1000 2600 in stock
ITF04-400 mouse human no 400 1100 on request
ITF04-1000 mouse human no 1000 2200 on request
ITF05-400 macaque  macaque yes 400 1300 on request 
ITF05-1000 macaque macaque yes 1000 2600 on request
ITF06-400 macaque macaque no 400 1300 on request
ITF06-1000 macaque macaque no 1000 2600 on request
ITF07-400 mouse mouse yes 400 1300 in stock
ITF07-1000 mouse mouse yes 1000 2600 in stock
ITF08-400 mouse mouse no 400 1100 in stock
ITF08-1000 mouse mouse no 1000 2200 in stock



Performance of biotinylated FcRn on different assay platforms

AlphaScreen(TM) , Perkin Elmer


Titration of rituximab (black, Kd 32nM) and human serum albumin (HSA, grey, Kd 850) biotinylated human FcRn using the Alpha Screen platform from Perkin Elmer. BLI, Octet ForteBio


Octet Platform, Fortebio


Kinetic analysis of binding of HSA and HSA K573P mutant on biotinylated human FcRn on the Octet platform from ForteBio.
Human IgG1 binds biotinylated FcRn from all species


Biacore, GE heathcare Life Sciences


Examples showing binding profiles for different types of antibodies to human, macaque and mouse FcRn. Binding behavior towards human and macaque FcRn was very similar. All antibodies showed highest binding towards mouse FcRn. Binding specificities for all antibodies were in agreement with published data (*Abdiche, Y. N. et al. 2014, mAbs, 7, 331-338). Biotin CAP Kit (GE Healthcare) was used with FcRn capture levels 90-100 RU and antibody concentration series: 25, 74, 222, 666 and 2000 nM. Running buffer: 20 mM phosphate, 150 mM NaCl, 0.05 % Surfactant P20, pH 6.0


List of publications where the FcRn were used:


Materno-fetal transfer of preproinsulin through the neonatal Fc receptor prevents autoimmune diabetes. 

Diabetes. 2015 Apr 27.


Regulation of immune responses to protein therapeutics by transplacental induction of T cell tolerance. 

Sci Transl Med. 2015 Feb 18;7(275)


Stabilisation of the Fc fragment of human IgG1 by engineered intradomain disulfide bonds. 

PLoS One. 2012;7(1):e30083.

PMID: 22272277


Ligand binding and antigenic properties of a human neon. 

FEBS J. 2008 Aug;275(16):4097-110.

PMID: 18637944


A strategy for batal Fc receptor with mutation of two unpaired cysteine residues. Bacterial production of a soluble functional human neonatal Fc receptor. 

J Immunol Methods. 2008 Feb 29;331(1-2):39-49.

PMID: 18155020


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