Bleaching zebrafish embryos

Materials:

Sigma
Sodium Hypochlorite, 10-13% , catalog # 42,504-4.

Boehringer Mannheim
Pronase, 5g catalog # 1459643

Method:

1. Make up bleach solution - 360 uL of NaOCl(10-13%) in 1L dH2O



2. Transfer embryos to clean dish or glass beaker



3. Incubate 5 min in bleach solution



4. Rinse embryos 1X in fish water



5. Incubate 5 min in bleach solution



6. Rinse embryos 2X in fish water



7. Transfer embryos into new petri dishes

Pronase

1. After bleaching, add 10 uL of 30mg/mL pronase (thawed from -20C and mixed as it does settle) to each petri dish and place into the incubator. Make sure embryos are not clumped together, which causes retardation, rather spread them throughout the dish. Keep pronase on ice, as it will digest itself as well as lose activity. EMBRYOS WILL NOT HATCH WITHOUT PRONASE.



2. Nest day, remove chorions and replace pronase water with fresh embryo media. >90% of embryos should be hatched. Those that are not hatched, pipet them against the side of the petri dish and they ususally fall out of their chorions.