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Surrogate Materials to Support Training in Biological Sampling and Detection in the Field


Surrogate Materials Can Evaluate the Entire Process
Figure 1.

Nationwide, first responders regularly encounter suspicious materials that might be biological threat agents.  Routine training and process evaluations help ensure operators, technologies, and workflows are working properly within the concept of operations (ConOps) (Fig 1).  

Biological test materials have the critical role of providing a realistic challenge material for the entire process.  However, the use of inactivated biological threat agents is limited for reasons including health and safety concerns, the potential for equipment contamination that can result in false positives during real events, limited availability of the materials, and the need for specialized sample processing facilities.  
To overcome these limitations, the National Institute of Standards and Technology (NIST) developed a modified Baker’s yeast strain (Saccharomyces cerevisiae NE095) to serve as a surrogate for biological threat agents during routing training and technology evaluation.  The NE095 yeast was successfully detected by potential users of the yeast, including public health and mobile laboratories, in an interlaboratory study.[1]  
Yeast sample
Figure 2.

In July 2015, suitability of the yeast material was demonstrated in Operation Vigilant Sample (OVS) IV, a functional field exercise led by Captain Bryon Marsh (Georgia National Guard 4th Civil Support Team (CST)) at the Guardian Centers, Perry, GA.  Local responders, state public health laboratories, CSTs, Environmental Protection Agency (EPA), and BioWatch applied state response plans in a biothreat scenario (putative Yersinia pestis).  

The CSTs deposited the yeast material onto stainless steel coupons (Fig. 2) that were then placed at pre-determined locations around the training site.  Sampling teams received just-in-time training and collected samples from the coupons (Fig. 3)

Mobile and public health laboratories successfully detected the yeast via quantitative polymerase chain reaction in samples from yeast-inoculated but not blank coupons.  

Surrogate Materials
Figure 3.
Credit: NIST

S. cerevisiae NE095 challenged the entire assessment process, from sample to answer, including results interpretation and reporting, and enabled exercise participants to demonstrate their ability to assess a biological material in the field while minimizing health and safety risks.  

Department of Homeland Security (DHS) Science and Technology Directorate funded this work under Interagency Agreement HSHQPM-14-X-00078 with NIST.

Check out the NIST Facebook page for more information.
Surrogate Materials
Figure 4.


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[1] Da Silva SM, Vang LK, Olson ND, Lund SP, Downey AS, Kelman Z, Salit ML, Lin NJ, Morrow JB.  Evaluation of microbial qPCR workflows using engineered Saccharomyces cerevisiaeBiomolecular Detection and Quantification.  2016, 7:27-33.  doi:10.1016/j.bdq.2016.01.001


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Created June 16, 2016, Updated February 20, 2020