 The compound then goes through the metabolic pathways and is used in the synthesis of the product studied.For example, a radioactively labeled form of leucine (3H-leucine) can be supplied to a group of pancreatic beta cells, which then uses this amino acid in insulin synthesis.Shortly after introduction of the labeled compound (usually about 5 minutes, but the actual time needed is dependent on the object studied), excess of the same, but unlabeled, substance (the chase) is introduced into the environment.