Reagent allows for rapid stabilizations and protection of cellular RNA against degradation. fixRNA allows for long term storage of the sample and effective isolation of RNA at any time. To protect RNA use only fresh tissues, blood (leukocytes), cell or bacterial cultures. Do not use frozen samples or samples stored without fixRNA reagent. To protect and stabilize whole blood we recommend Universal Blood RNA Kit (E3594) and Lyse Blood buffer included in the kit.