Identification of the pathogenic microbe is essential for selection of the most appropriate treatment in the majority of cutaneous infections. Historically, the diagnosis of cutaneous pathogens has been based on the results of immunological studies, lesional culture, and/or microscopic examination of tissue samples, in combination with histochemical stains (i.e., PAS, Gram) or immunohistochemical studies. Microscopic review of clinical specimens allows for rapid microbe detection. However, this method lacks sensitivity and specificity, and typically results in a preliminary determination only. In addition, not every pathogen is identifiable by microscopic analysis, and special stains are often less sensitive than culture methods. Thus, definitive characterization requires growth of the pathogen in culture, which remains the gold-standard methodology for laboratory diagnosis of microbial infection. While the latter generally demonstrates improved sensitivity and specificity as compared with histopathological examination, microbe growth may require days to weeks of culture, delaying both diagnosis and the institution of appropriate therapy. Further complicating matters is the fact that not all pathogens grow outside of their host.