I need to isolate RNA from Drosophila head. I basically chop the head off and first homogenize it with a homogenizer (similar to this: http://www.omni-inc.com/omni-tissue-homogenizer-th-package-p-11.html) and further homogenize it with 22G needle in TRIzol reagent. I use TRIzol RNA isolation for larvae brain a lot and have no problem with the method itself. However, with adult I got really low RNA concentration which is weird.
I thought that maybe I have problem with homogenization itself, or I overlook something (such as extra centrifugation or different kind of homogenization etc). Does anybody have experience with it? Thanks.