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

In cholinergic neurons, acetylcholine is synthesized from choline and acetyl-coenzyme A (acetyl-CoA). Following depolarization, acetylcholine is released in the synaptic cleft via synaptic vesicles and activates muscarinic and nicotinic receptors located on postsynaptic membranes. Acetylcholine released in the synaptic cleft is rapidly hydrolyzed into choline and acetate. Since choline is not de novo synthesized and thereby only made available through diet uptake, choline is recycled back into the cells in order to regenerate acetylcholine. For this purpose, choline is taken up by the high affinity choline transporter (CHT).