Here is our procedure for mouse muscle RNA isolation.

"RNA was isolated by mechanical homogenization of muscles in TRI Reagent followed by a Qiagen RNeasy clean-up kit (Qiagen, Valencia, CA, USA)." From a mouse quadriceps, you will get a ton of RNA. However, because of regional variations in fiber type, it is important that you sample from the entire muscle. If you are uncertain about your dissection technique, recruit someone who knows how.

Thank you very much for your answer Gordon.

Do you also add a proteinase K step during your extraction protocol?

No, we do not have a proteinase K step.