RNA purification kits and reagents are available from a variety of suppliers, tailored for the convenient and effective isolation of RNA. These include kits, buffers, and solutions for isolating not only total RNA, but also mRNA, miRNA, and exosome RNA. These ready-to-use kits also allow for the removal of unwanted elements such as DNA and ribonucleases, leaving contamination free RNA that are well-suited for use in applications studying gene expression, including RT-PCR, microarrays, and sequencing.