Peichuan Zhang Answered Feb 13, 2014
Department of Biology, The Pennsylvania State University, USA
Hi Farzane,
We just soaked the samples in the trypsin solution overnight at room temperature (not at 37 degrees) --- this should work well enough.
For your other question --- we used ethanol instead of formaldehyde to fix embryos. Maybe this helps to avoid over-fixing. I'd recommend you to open the abdomen of the embryos with scissors after sacrificing them in your experiments.
Best,
P