Similar to yield, RNA integrity depends on several parameters, such as tissue type, time from resection until fixation, fixation time, processing protocol, age and storage conditions of the PFPE block. For examples of RNA integrity values from rat tissues under ideal workflow conditions, see Groelz et al., Exp Mol Pathol. 2013 Feb; 94(1). For examples of RNA integrity from clinical samples, see Viertler et al., J Mol Diagn. 2012 Sep; 14(5).