A general method for high-quality RNA isolation from metabolite-rich fruits

The isolation of high-quality RNA from fruit tissues is often difficult due to the abundance of polysaccharides, phenolics and other metabolites that can negatively affect both the quality and yield of isolated RNA. Here, we describe several modifications to an existing method that can be used to isolate RNA from the pulp of several different fruits that contain large amounts of metabolites. This method, in contrast to other extraction protocols tested, was successfully used to extract large quantities of high-quality total RNA from two developmental stages in all species tested, as assayed by spectrophotometry and electrophoresis on denaturing agarose gels. This RNA was also suitable for use in downstream applications such as reverse transcription-polymerase chain reaction and real-time quantitative RT-PCR. The method described here could likely be used for studying gene expression during the development and ripening of a wide variety of fruit tissues, especially in cases where other methods fail to yield suitable RNA.

► High-quality RNA isolation from fruit is particularly challenging.
► An improved method is described for RNA isolation from metabolite-rich fruits.
► RNA isolated by this method can be used for downstream applications.