The anticipations of molecular diagnostic systems becoming the new gold standard for patient diagnosis have largely gone unmet and blood culture still remains as the de facto method to determine the course of patient treatment [2], [8]–[12]. In light of the focus on molecular diagnostics, efforts to develop rapid techniques to directly test pathogen susceptibility are lacking [13]. In fact, we believe direct susceptibility testing of such blood-borne pathogens may be of greater importance than species identification via genotyping as the selective pressures of broad-spectrum antibiotic use have contributed to the increased incidence and virulence of antimicrobial resistant septicemia [14]–[18]. Universal susceptibility testing by genotyping for resistance is inferior to traditional phenotypic methods, as the microorganisms must be screened for a multitude of resistance cassettes. This approach has intrinsic vulnerabilities as more complicated and genetically diverse mechanisms of antimicrobial resistance have remained elusive [18], [19]. Herein, we describe a method of direct susceptibility testing by monitoring phenotypic bacterial load via real-time PCR of spiked blood samples post-exposure to an array of antimicrobials. This method combines rapid molecular diagnostic detection with the traditional benefits of phenotypic testing to achieve universal susceptibility analysis, minimum inhibitory concentration determination, and pathogen identification in blood in less than 24 hours.