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

Fifty different chemokines exert their effects through twenty different chemokine receptors, belonging to the superfamily of G-protein coupled receptors (GPCRs) suggesting a certain level of promiscuity among the different receptors. All chemokine receptors couple to the G_i protein. Chemokines were first identified by their ability to mediate leukocyte chemoattraction. Apart from regulating the migration of leukocytes, they seem to be major players during inflammation and immunity.