FRET-based assays for neurological disease and diagnostics

Förster resonance energy transfer (FRET) is one of the most promising techniques to affirm the functioning of the cerebral-neural system. The increase in neurological diseases calls for the need to foster techniques to diagnose diseases affecting the normal functionality of the brain. FRET variations involve different molecules, protein-protein (as in FRET), antibody-protein (in TR-FRET), single-molecule FRET microscopy (smFRET), different analysis spectra, visible and near-infrared range (NIR-FRET). This technique is also used in collaboration with NMR, Fluorescence microscopy, SAXS (Small and wide-angle X-ray scattering), and FRET-Fluorescence correlation spectroscopy to enhance the analysis results. The current chapter encapsulates the most recent findings of different types of FRET assays for the diagnosis of various neurological disorders with a special emphasis on Time-resolved FRET. FRET assay, along with Flow cytometry has been used for quantitative estimation of protein aggregates, which is a common manifestation of various neurological diseases. This chapter additionally highlights a combination of FRET and TIRF for probing GPCR interactions, which are the largest biological transmembrane signaling molecules.