Subculturing astrocyte from E15 days mouse embryo - Technique (May/01/2005 )

I have a problem when I subculture astrocytes from E15days mouse embryo. After incubating them with 0.05%trypsin-EDTA (less than 2mins, 37oC), I still find that most of them are not attaching to the plate on the following day. It seems to me that they are dying. Any other milder ways suggest to me?

in papers you can find much easer protocol which will works better (without "incubating them with 0.05%trypsin-EDTA (less than 2mins, 37oC)"), because 2 min in 37°C with 0.05% trypsin is too much even for P1-2 mice
or you could just skip this step

have you coated your tissue flasks? may you try for the first time gelatine?
good luck