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

BDNF and NT-4 belong to the neurotrophin family which also includes NGF and NT-3. These neurotrophins bind two groups of receptors. The p75^NTR receptor is common to all four neurotrophins and is a member of the tumor necrosis factor receptor family. The tropomyosin-related kinase (Trk) receptors are receptor tyrosine kinases (RTKs) and three receptors form this family: TrkA, TrkB, and TrkC. TrkA is activated by NGF binding, TrkB by that of BDNF and NT-4, while TrkC is stimulated by the binding of NT-3.