Fc Receptor Assays Using Gator Bio HIS XT Biosensors

Characterizing IgG interactions with Fc gamma receptors is a high-priority measurement across antibody discovery and development, but low-affinity receptors like FcγRII and FcγRIII are notoriously difficult to measure cleanly. This application note shows how the Gator HIS XT biosensor, featuring the NovoBody™ single-domain capture molecule developed with Monod Bio, delivers clean 1:1 binding kinetics for FcγR assays on Gator Plus+ and other Gator instruments.

Inside you’ll find:

• Optimized Loading Protocol: Guidance on loading FcγRIIA/CD32a to 0.5 nm shift to eliminate mass transport limitation and rebinding artifacts
• Clean 1:1 Kinetics: Well-resolved association and dissociation curves with R² values above 0.99, validated against published SPR literature values
• Temperature Flexibility: k_on remains stable from 10°C to 40°C, while k_off responds predictably to temperature
• NSB Troubleshooting: His-Ubiquitin blocking dramatically reduces non-specific binding when antibody sample quality is a limiting factor
• Biosensor Reusability: 10+ regeneration cycles with less than 15% signal loss for high-throughput Fc engineering workflows