The RiboMinus™ Human/Mouse Transcriptome Isolation Kit constitutes a novel purification system that removes RNA from total RNA samples. Large ribosomal RNA molecules to enrich the entire spectrum of mRNA species. This kit removes >95% of 18S and 28S rRNA molecules from total human or mouse RNA (Figure 1), independent of current polyA+ purification methods. This increases the expression of mRNA species, including non-polyA tail fragmented mRNAs and other regulatory RNAs that cannot be purified by polyA selection methods. Purified RNA is suitable for multiple downstream applications, including library construction, RT-PCR, and microarrays (Figure 2).