digitonin lysis buffer - (Jun/09/2008 )

Hi, could you please tell me whether I can prepare digitonin lysis buffer in the same way as NP-40 lysis buffer, or should I add something else to it? ( what I do is: 50mM TrisCl pH8,150mM NaCl,0.1%NP-40). Thank you for your help!

I use the following for Hepa1C1C7 Cell lysis

(Per 100ml)
8mg digitonin
84mg EDTA tetrasodium Salt
80 ml H2O

Mix and bring to 100ml with H2O