This two-step approach resulted in a lower limit of detection from a starting inoculum of 1 cell/mL. Data suggests that enrichment with spent culture filtrate followed by physical separation and capture by the DNA aptamer cocktail can be utilized alongside current diagnostics as a pre-analytical processing tool. Reliable and time-sensitive detection of a biological contaminant within the food network is essential to advise management and treatment procedures during a potential outbreak. The gold standard for microbe detection is successful cultivation of the agent in vitro; however, this remains a challenge for intracellular pathogens as many are either slow-growers or dormant in vitro. F. tularensis, a possible aerosol and biocontaminate in food, requires incubation for 2�C4 days at 37��C when supplemented with cysteine, thioglycolate and/or blood. Furthermore, culture of F. tularensis in biological samples is also difficult to achieve in broth culture, unless a high starting inoculum is used. Few studies have focused on the development of tools capable of detecting F. tularensis in food and the environment. This is a significant concern given the potential of F. tularensis to contaminate food. A 2009 study by Day and Whiting utilized a macrophage cell culture model to isolate and enrich for F. tularensis in infant formula, Tubacin distributor liquid egg whites, and lettuce. Day��s and Whiting��s study was unique in the fact that they took advantage of F. tularensis�� niche cell, where the pathogen would efficiently replicate inside. Once noninvasive resident bacteria were discarded from the cell culture medium and sufficient time was allowed for F. tularensis growth, realtime PCR analysis could identify as little as 10 CFU/mL of F. tularensis in infant U0126 formula and lettuce and liquid egg whites. Although this method successfully enhanced the growth of and separated F. tularensis from food bacteria, it required specialized training in cell culture maintenance and access to equipment. This may not be feasible for field testing. During the course of our investigation to create an improved cultivation medium for F. tularensis, we rediscovered initial experiments and subsequent observations reported by Halmann et al.. Halmann et al. report the presence of a Growth Initiating Substance from low inocula of F. tularensis that enhanced the growth of dormant F. tularensis cells when supplemented in traditional culture medium. Similar to the Halmann studies, we have also shown that supplementation of standard medium with 10% spent culture filtrate results in F. tularensis enhanced growth in pure and mixed cultures.