Antibodies are critical tools in research, diagnostics and therapeutics due to their exquisite specificity and sensitivity.
For example, research in target validation for drug discovery has relied on antibodies to identify proteins in a variety of assays including enzyme-linked immunosorbent assay (ELISA), cell-based ELISA, Fluorescence-Activated Cell Sorting (FACS), western blot, and immunohistochemistry (IHC).
In the past decade, significant progress has been made in antibody generation against G-protein coupled receptors (GPCR) including functional antibodies. However, producing high affinity and specific GPCR antibodies remains challenging. First of all, due to their complex seven-transmembrane protein structure, only limited small extracellular epitopes are available as antigens or for panning, Secondly, cross-reactivity is a prevalent issue shared among GPCR antibodies attributed to primary sequence and structural similarities among the large number of GPCRs encoded in our genome. To compound the difficulty, it is technically challenging and nuanced to develop and run cell-based assays to profile antibodies for on-target and off-target activities against GPCR targets. This applies to both functional and binding assays for GPCRs.