hello everyone ,

I'm currently working on extracting RNA from frozen tumor tissue that was snap-frozen in liquid nitrogen and stored at -80°C. I've attempted a protocol involving cutting a small piece of tissue and adding 500 μl of TRIzol reagent followed by chloroform. However, I've encountered an issue with obtaining a low RNA Integrity Number (RIN) of less than 5.

Does anyone have a reliable protocol to improve the quality of RNA extraction?

Thank you, Shahd