rna isolation - (Oct/27/2010 )

Hi all

I am isolating rna from leaf of plant and I am always in problem regarding the grinding of the tissue properly. I use liquid nitrogen for grinding the tissue but i am very much interested to know whether there is any method like where i dont need to use liquid nitrogen and still get my work done- homogenization?

I have read of bead based homogenizers, does any one have any idea whether these require liquid nitrogen?
Plz help.

I'm not really familiar with plant biology, but is this is a common conventional method or are you using a kit?