What is the composition of Buffer RWT?

The exact composition of Buffer RWT is confidential. Buffer RWT is a proprietary component of, for example, the miRNeasy Mini Kit and the RNeasy Plus Universal Kit. Guanidine salt and ethanol are important ingredients in Buffer RWT. Ethanol is added by the user prior to the first use of the kit. Buffer RWT is a stringent washing buffer used after preclearing the sample with QIAzol Lysis Reagent, especially if isolation of small RNAs, for example, microRNAs or RNAs from formalin-fixed tissue, is desired