Detecting DNA contamination from exon/intron/intergenic proportions

[PaulyL]

Hi All,

I'm working with poly-A selected RNA-Seq data. Is it possible to figure out whether there is DNA contamination in my data by looking at the proportions of tags mapped to exons, introns and intergenic regions? More generally, in a typical RNA-Seq data set, what proportions of tags should be mapped to exons, introns and intergenic regions?

Thanks.
Paul