Native Cell Surface Analysis for Membrane Proteins

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Membrane proteins like GPCRs, ion channels, and solute transporters are notoriously difficult to purify without harsh detergents altering their native properties. This makes traditional biophysical characterization challenging. SPR microscopy (SPRm) resolves this limitation by measuring ligand affinities and kinetics directly on intact cells.

• Native Environment: Study targets without extraction or purification.
• Rapid Evaluation: Accelerate screening for both small and large molecules.
• Label-Free Detection: Eliminate artifacts from fluorescent or radioactive tags.
• Cell Versatility: Compatible with both adherent and suspension cell lines.

Unlike conventional surface plasmon resonance (SPR), SPR microscopy (SPRm) measures ligand binding on whole cells by detecting membrane micro-deformations. The system simultaneously monitors hundreds of regions of interest (ROIs) as independent channels within a single flow cell, leveraging automated filtering and background correction to generate high-throughput sensorgrams. This method delivers binding kinetics and affinities that correlate strongly with traditional, labor-intensive approaches like radioligand assays.

In Vitro Characterization of Agonist and Antagonist Peptide Binding Interaction Kinetics to GLP-1R in HEK293T Cells Using Surface Plasmon Resonance Microscopy

ACS Med. Chem. Lett. 2026, 17, 5, 963–972

Discovery of Potent and Brain-Penetrant Inverse Agonists for GPR61, an Orphan G Protein-Coupled Receptor

J. Med. Chem. 2026, 69, 6, 7393–7404

The application note below compares the kinetics and affinities of several different ligands to their cognate membrane protein targets in both live and fixed cells, showing that cell fixation does not significantly alter binding.