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DNase I digestion - how long the fragments are at the end??? (May/07/2009 )

hello out there,

have a question about dnase digestion: after performance of standard dnase I digestion of my RNA preparation, how long are the DNA fragments (bp) in there?

thanks in advance for help


~10 bp maybe?

Understanding Life One protein at a time...

-James Chou-

"on average producing tetranucleotides" (
don't know if that's true, though... DNAse1 cuts adjacent to C or T, that would be dinucleotides on average (or am I wrong?).


It depends on how much DNase I you add and how long you incubate it. Just run an aliquot of the digested in a gel to take a look. You will get two pieces of important info from the gel - 1) is all your RNA gone (most DNase I has RNase activity)? 2) is the DNA digestion gone to completion (if the degraded DNA fragments are <200bp, you are fine with RT-PCR). I always use minimal amount of DNase I and incubate at RT for 30-60min, RT-PCR always works.