The past decade has seen remarkable technical advances in infectious disease diagnosis, and the pace of innovation is likely to continue. Many of these techniques are well suited to pathogen identification directly from pathologic or clinical samples. This curriculum will therefore explore the principles and application of these strategies for the microbial diagnosis, including polymerase chain reaction (PCR), real-time PCR, multiplex PCR, LAMP, PCR-ELISA, monoclonal antibodies, mass spectrometer, fluorescence microscope, confocal microscope, DNA sequencing, DNA microarrays, in situ hybridization.