how to do histone extraction - (Sep/27/2010 )

Hello all,
i want to check acetylation status of histone H3 and H4 on tumor samples.
I am in dilema whether to do nuclear extraction or histone extraction for western blot to check acetylation status of histone H3 and H4 .
I know how to do nuclear extraction but never done histone extraction.
Can anybody suggest me which extraction if better for checking histones.
Also please tell me how to do histone extraction.

thank you.

See http://www.abcam.com/ps/pdf/protocols/Histone%20extraction%20protocol.pdf

or use a histone extraction kit from active motif or epigentek