Selected remaining juveniles ~2 month and incubated with 20 µM EdU from Click-iT Kit for 3h (stock concentration is 10mM, 2µL/1000µL). Relaxed with MgCl2 for 30min in cold room and fixed with 4% PFA for 1h in cold room + 1h at RT. Permeabilized with PBS+Triton-X and stored at 4 °C in PBS.