What is the best kit to extract RNA from gram negative bacteria to get high quality RNA of at least 7 (RIN VALUE)? At the moment I am using (Qaigen kit) but it does work for one strain and doesn't for the other, so any recommendation please?
I had the same experience with G(-) bacteria using Qiagen kit or trizol. The most consistent results was from a modified hot phenol technique. I started lysis with the RLT-BME and then phenol extraction at 60oC, followed by the routine phenol-BCP extraction. If you are interested in, let me know. I might have the protocol somewhere.
I've worked with PureLink RNA kit (Life Technologies) when I need to isolate bacterial RNA from Gram negative microorganism. I obtained really good results related with RNA amount and quality (checked with Experion from Bio Rad).