Schematic of pulse-chase experiment. MIN6 cells expressing GFP-Rab3 and NPY-Halo were first labeled with JFX650 Halotag ligand for 20 min (red) to visualize all existing granules and block Halotag reactive sites. The dye was then washed out and new NPY-Halo was synthesized by cells for 1 h (gray), which was then selectively labeled with the JFX549 Halotag ligand (yellow). After the specified chase time, the cells were fixed, processed, and imaged to determine the kinetics of Rab3 acquisition onto insulin granules.
