Norgen’s Fecal Swab Collection and Preservation System is designed for collection, ambient storage and transport of nucleic acids from stool specimens. The Fecal Swab Collection and Preservation System tubes contain Norgen’s Stool Preservative in a liquid format. The user simply collects the specimen using the provided swab, and then transfers the swab into the Stool Preservative. The Stool Preservative prevents the growth of Gram-negative and Gram-positive bacteria and fungi, and also inactivates viruses allowing the resulting non-infectious samples to be handled and shipped safely. In addition, the Stool Preservative eliminates the need to immediately process or freeze samples and allows the samples to be shipped to centralized testing facilities at ambient temperatures. The components of the Stool Preservative allow samples to be stored at room temperature for over 2 years for DNA and 7 days for RNA. To extend the stool RNA stability in the preservative, storage at -20°C or -70°C is recommended upon arrival at the testing facilities until RNA purification.
Figure 1. Norgen's Best-In-Class Preservation. Summary of community shifts in response to stabilizing solutions over a 14-day storage period. Bray-Curtis distance towards the reference for each patient grouped by stabilizing solution. Median and 5th-to-95th percentile ranges are shown for both interaliquot and interpatient variability (adapted from Plauzolles et al, 2022). Norgen is the most similar to frozen stool samples, over 11 other sample collection and storage methods..
Figure 2. Integrity of Total Stool DNA and RNA Isolated from Preserved Stool Samples. DNA and RNA were isolated from 200 µL of preserved stool from 4 different donors (lanes A to D) stored at room temperature at the indicated time points (DNA at 27 months and RNA at 7 days) using Norgen's Stool Nucleic Acid Isolation Kit (Cat# 45600). Next, 10 µL from the 75 µL eluted nucleic acid was loaded onto a gel for visual analysis. High integrity stool DNA was isolated from preserved stool samples that were stored at room temperature for 27 months, and high integrity RNA was isolated from stool samples stored for 7 days at ambient temperature. Lane M is Norgen's HighRanger 1 kb DNA Ladder (Cat. 11900).
Figure 3. Monitoring the DNA stability of Adenovirus (Ad5subE1) Spiked into Preserved Stool Samples using TaqMan Real-Time PCR Assay. Preserved stool samples were spiked with 6 x 109 pf/mL of Adenovirus, and 200 µL samples were removed at the indicated time points. The stool DNA was then isolated using Norgen's Stool DNA Isolation Kit (Cat. 27600). Next, 2 µL of DNA template from each 50 µL of elution was used in a 20 µL PCR reaction to detect the Adenovirus DNA. The stool preservative was shown to stabilize Adenovirus DNA up to 21 weeks at ambient temperature, indicating that Norgen's Fecal Swab Collection and Preservation System provides a safe and convenient sample transportation system.
Figure 4. Hierarchical Clustering of Stool Samples at Phylum Level Under Different Storage Conditions. The microbial composition from the stool samples preserved in Norgens Stool Nucleic Acid Preservativedid not differ significantly to that of controls (fresh stool from Day 0 at RT) over a 2 day period, while non-preserved stool samples showed a greater difference in the dendrogram from the original stool profile.
Figure 5. Difference In Top 5 Abundant Microorganisms at Phylum Level Compared to Fresh Stool (Day 0). Abundance of Firmicutes, Bacteroidetes and proteobacteria from the preserved stool sample was higher than non-preserved (NP) compared to the fresh stool after 2 days storage at RT, indicating that the microorganism profiles from the preserved stool are much closer to the fresh stool sample (Day 0).
Figure 6. Relative Abundance of Bacterial Genera Between Preserved And Non-Preserved Stool Samples Stored at RT For 2 Days.Stool samples preservedusing Norgens Stool Nucleic Acid Preservative showed a closed relativeness to the fresh stool sample (Day 0) compared to the non-preserved sample.
Figure 7. Correlation between duplicate bacterial metagenomic reads using (A) Fresh stool (day 0) and preserved stool at RT for 2 days and (B) Fresh stool (day 0) and non-preserved stool at RT for 2 days. A greater R2 was observed for Fresh stool (day 0) and preserved stool, suggestive of higher consistency between fresh stool sample and preserved stool sample.
Stability of Stool Nucleic Acids at Room Temperature
2 years for DNA
Up to 7 days for RNA*
* The RNA stability will vary depending on the samples
Storage Conditions and Product Stability
The Fecal Swab Collection and Preservation System (Bulk Format) can be stored at room temperature for up to 2 years without any reduction in kit performance. The expiry date for the swabs is written on the swab wrapper.