Pulse-chase analysis

In biochemistry and molecular biology, a pulse-chase analysis is a method for examining a cellular process occurring over time by successively exposing the cells to a labeled compound (pulse) and then to the same compound in an unlabeled form (chase).

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.

However, the movement of the labeled insulin produced during the pulse period could still be tracked within the cell.

George Palade used pulse-chase of radioactive amino acids to elucidate the secretory pathway.

Pulse-chase analysis of auxin signal transduction in an Arabidopsis thaliana wildtype and an axr2-1 mutant. Wild-type and axr2-1 seedlings were labeled with 35S- methionine , and AXR2/axr2-1 protein was immunoprecipitated either immediately after the labeling period (t = 0) or following a 15-minute chase with unlabeled methionine (t = 15).