Extracellular antibodies are ideal research tools for cell-surface proteins.
No permeabilization/fixation because using extracellular antibodies allows you to work with live cells!
Benefits of live cell imaging:
✓ Monitor cell movement
✓ Study protein transport across the cell
✓ Investigate protein internalization
NTS1 and NTS2 belong to the 7-transmembrane domain, G protein-coupled receptor (GPCR) superfamily while the third neurotensin receptor NTS3 (also called Sortilin) is a type I membrane protein with a large extracellular domain. Both NTS1 and NTS3 bind neurotensin with high affinity while NTS2 binds it with low affinity.