Phenol wash necessary? - (Jul/09/2012 )
Although I have done tons of DNA and RNA extractions in past 8 years, I have never done following. If I just want to check quality of DNA, after RNase and proteinase K treatment, on agarose gel, is it necessary to remove these proteins by phenol wash followed by DNA precipitation before agarose gel electrophoresis? In other words, would RNase and proteinase K interfer with agarose gel electrophoresis of DNA?
I ran a gel meanwhile and it gave goo bands at my expected sizes. I thus came to the conclusion that there is no effect of RNase and proteinase K on the agarose gel performance of the DNA
Haha, yeah, if you think about how much DNA/RNA you are typically extracting and the quantities of proteinase K and RNase that go into the reaction (let alone are eluted out) then you'll get a good idea that they will normally be swamped out by the nucleic acids. What's likely to happen is that a tiny amount of signal in the gel will be attributable to proteins but they will not migrate at the same place as the nucleic acids.
Long story short: there's likely to be no discerible effect of protainase K or RNase on your gel.