Protocol for RNAse treatment of genomic DNA - pre-RT-PCR (Aug/24/2006 )

I need some advice on developing a protocol. I am currently developing a transgenic mouse line and I am using RT-PCR as one method of detecting the genotype of the assumed homozygous population. I am using a pretty standard method of isolating the genomic DNA from tail cuts of 21 day old mice. However, I do not have any RNAse in the buffer and my boss thinks that it would be better to treat the DNA after it is isolated. I know that you can treat isolated DNA was RNAse and then precipitate it out with ammonium acetate. However, this requires re-precipitating the DNA with ethanol and the possibility of loosing the sample. I was curious if anyone knows of a better way or if there is an RNAse that doesn't have to be removed prior to RT-PCR. Also, is either RNAse 1 or RNAse A better/worse for samples to be used for RT-PCR? Thanks!

I'd add it to the buffer before isolating the DNA. This is a common practice with most commercial kits and may enhance the efficiency of your genomic recovery (regardless of method). Like you said you will also reduce the risk of sample loss or DnA degradation possible with additional manipulations.

hmmmm

I'm confused

why are you using RT-PCR on genomic DNA? RT=reverse transcriptase; that method involves RNA that has been reverse-transcribed into cDNA

or does your "RT" stand for something different?