Figure 2. Yield and Quality of Purified Stool RNA. Total RNA was isolated from 200 mg of human stool using Norgen's Stool RNA Purification Kit Dx and a leading competitor kit. Comparisons were then made based on yield, and A260:A280/A260:A230 ratios measured using the NanoVue Plus™. In Panel A it can be seen that both kits isolated RNA with high A260:A280 ratios (all samples were found to be above 1.8 and below 2.2). In Panel B, Norgen's kit was found to isolate RNA with a high A260:A230 (with all samples once again falling in the 1.8-2.2 range). The competitor kit, however, was found to isolate RNA with extremely low A260:A230 ratios, with none of the samples displaying a A260:A230 ratio higher than 0.20. The results in Panel C are in agreement with the gel photo from Figure 1, and Norgen's kit was found to isolate higher amounts of RNA, with an average yield of 14.58 µg, compared to the competitor’s average of 12.26 µg.

Figure 3. Detection of Bacterial Stool RNA using 16S Primers. Total stool RNA was isolated from 200 mg human stool samples using Norgen's Stool RNA Purification Kit Dx and a leading competitor’s kit. Five microliters of purified RNA was used in a 20 µL reverse-transcription reaction using Invitrogen's Superscript III system with 16S reverse primers. The cDNA generated was then used in a qPCR reaction involving Norgen's 2X PCR Mastermix spiked with SYBR green (Bio-Rad), using 0.3µM of primers against bacterial 16S. As can be seen in the amplification plot, Norgen's kit outperformed the leading competitor's kit by on average 1.5 Ct values. This indicates that Norgen isolated higher quality and yields of RNA from stool, that can be used in an array of downstream applications.