How to extract protein from a bone marrow sample - protein from bone marrow (Jun/22/2007 )

Hi,
I am working with bone marrow samples for the first time. I have frozen bone marrow cells to work with. I tried RIPA buffer and then sonication before, but it is not working to well for me.
1. when I use tubulin as loading control, there is no band
2. faint band for ponceau S stain
3. coomassie looks ok but higher kDa bands are missing and/or very faint.

Any suggestions? Thanx!

1. Freeze-thaw the marrow.
2. Freeze the marrow in buffer with protease inhibitors using liquid N2, then crush in a mortar. thaw and proceed as usual.