User contributed: Glucagon receptor, Biorbyt, orb6093

We here review a publication from Novo Nordisk and University of Copenhagen providing a head-to-head comparison of all commercially available antibodies against the glucagon receptor (GCGR) (Bomholt et al., Communications Biology, 2022).
The authors systematically evaluated 12 commercial antibodies (Table S1) in HEK293 cells transfected with mouse or human cMyc-tagged GCGR cDNAs and studied liver sections from Gcgr+/+ and Gcgr-/- mice. Autoradiography, RNA-sequencing, and single cell RNA-sequencing were used as antibody independent approaches to support the findings obtained with IHC.
Transfected cells were permeabilized with methanol.
All GCGR antibodies, including this one from Biorbyt, gave overlapping staining with the cMyc antibody, demonstrating the ability to specifically recognize recombinant GCGR in transfected cells.
No staining was seen in control transfected cells or cells without primary antibodies (Fig. 1).
The antibodies were also checked for their ability to detect membrane bound GCGR by staining unpermeabilized HEK293 cells transfected with human GCGR and fixed in 4% PFA.
The Biorbyt antibody (Antibody 3 in the paper) also showed positive staining of membrane bound GCGR (Fig. S1)
The antibodies were subsequently evaluated using formalin-fixed and paraffin-embedded liver sections from female Gcgr+/+ and Gcgr-/- mice. However, the Biorbyt antibody showed no specific GCGR staining (Fig. 2a)
However, the Biorbyt antibody gave a positive signal in IHC on paraffin embedded human liver tissue from patients with NASH (Fig. 2S).
In conclusion, the Biobyt antibody receives a 4 star rating in immunostaining based on its ability to specifically recognize GCGR in transfected cells and its positive signal in the human NASH samples.