histone modification-ChIP analysis - selection of proper internal control for repressed state of gene (Jan/28/2008 )

hi!
I performed ChIP analysis using h3k9me Abs to check for the repressed state of my gene of interest,but could not decide which internal control should i select? As i think the internal control should come from a constitutivly repressed region or some tissue specific gene repressed in my tissue of selection
suggestions are invited.
thanks in advance

Hi,
its me again. I am still inn search of any answer.Please help if you have any suggestion.
thanks.

#1 Go to pubmed and look for papers published where they use those
antibodies successfully in the cell lines you are using.
#2 If you amplify heterochromatic repeats near chromosome centomeres
these should always give positive results. But since the region is repetitive it will just tell you if your technique is working and isn't very quantitative.