Stabilization of biothreat diagnostic samples through vitrification matrices

• We evaluate stability of Y. pestis nucleic acid in CloneStable® and RNAStable®.
• We evaluate VEEV nucleic acid in CloneStable® and RNAStable®.
• We examine protein stability of Y. pestis in CloneStable® and RNAStable® by ECL.
• ECL and qPCR assays’ precision are not affected by CloneStable® and RNAStable®.

Diagnostics for biothreat agents require sample shipment to reference labs for diagnosis of disease; however high/fluctuating temperatures during sample transport negatively affect sample quality and results. Vitrification additives preserve sample integrity for molecular-based assay diagnostics in the absence of refrigeration by imparting whole molecule stability to a plethora of environmental insults. Therefore, we have evaluated commercially available vitrification matrices' (Biomatrica's CloneStable® and RNAStable®) ability to stabilize samples of Yersinia pestis and Venezuelan Equine Encephalitis Virus. When heated to 95 °C in RNAStable®, Y. pestis had a 13-fold improvement in detection via real-time PCR compared to heated samples in buffer. VEEV, in RNAStable® at 55 °C, had a ~ 10-fold improved detection versus heated samples in buffer. CloneStable® also preserved Y. pestis antigens for 7 days after exposure to cycling temperatures. Overall, RNAStable® and CloneStable® respectively offered superior stabilization to nucleic acids and proteins in response to temperature fluctuations.