Question

Provide one reason why you would use a radioactive ligand and NOT a GFP tag when performing a general assay to elucidate specific binding of a ligand to its receptor.

Answer 1

A radioactive ligand is used and not GFP tag while performing a general assay for general binding of ligand to its receptor because it helps in identification of the exact binding because as soon as the ligand binds to its receptor, it releases the energy. Hence it is more effective as tracer and hence it is even easy to detect the radioactivity. With the radioactive isotope, it becomes very easy to detect the pathway of the substance meaning the movement of the ligand and how and when it binds to the receptor.