Micro Scale Thermophoresis (MST) uses local heating to induce movements in molecules or complexes. By following the movement in time at different molecule concentrations the equilibrium constant can be determined. There is not need for immobilization or labelling in the high end instruments. For the less advanced instruments one of the components has to be labelled.
Bio Layer Interferomtery (BLI) uses a white light beam that directs the light to the end of a sensor tip with two refractive layers. The ligand is immobilized to the very tip and dipped in solution. When the layer thickness changes the interference pattern between the two refractive layers changes. In this way a full kinetic profile can be made. In addition concentration measurements and antibody classification are some of the possibilities.
Surface Plasmon resonance (SPR) uses light to induce surface plasmons on a gold layer. These plasmons are sensitive for the binding of biomolecules to the gold surface. By immobilizing a ligand, a new baseline is made and subsequent analyte binding will give more signal. Full kinetic profiles, epitope tagging and concentration measurements are possible with SPR.
Cell-based assays are not always easy. Individual cells can react differently to external stimuli and following the binding and/or internalisation of added ligands is not always easy. The LigandTracer instruments of Ridgeview can follow a group of cells and measure the binding or internalisation of (radio)labelled ligands.