This link is useful

https://www.dnagenotek.com/ROW/support/collection-instructions/oragene-dna/OG-500andOG-600.html

Regards

Thanks , but i want to extract RNA from the same saliva which we have

we already extracted the DNA and sequenced the genes of interest.

Hi Alshimaa!

I feel that trying to get RNA out of saliva will be a challenge mostly because of the enzymes that are chewing it all up but if you want to try I would do a trial sample with Trizol LS or Phenol/ Chloroform pH of around 4.5 extraction. Don't forget to do a DNaseI treatment after the extraction. If you use a bioanalyzer to see how the RNA looks or get a RIN score, the RNA might be poor but I would go ahead and RT qPCR it. But if the RNA is showing up in small pieces it may be hard to qPCR. Good luck!