Raring embryos

1) Sort out healthily dividing embryos at 4- or 8- cell stage. Cleavage error occurs to some embryos, especially eggs from older embryos.

2) Transfer embryos to plastic dishes coated with 2% agarose/MFSW (see materials). 300~400 embryos/3.5 cm dish will will be maximum.
Add 1/2000~1/4000 volume of PS (penicillin/streptomycin SIGMA P0781, 10,000 unit/ml for penicillin and 10 mg/ml streptomycin) to sea water if your culture more than 24 hours. It is to avoid bacterial growth, which induces metamorphosis. Changing sea water once in the second day may help to prevent bacterial contamination.

3) Incubate at 18°C. Agitation is not important. 16°C is useful to slow down development (blastula~early gastrula).