Oligonucleotide and DNA Microarrays: Versatile Tools for Rapid Bacterial Diagnostics

The rapid and unambiguous detection and identification of microorganisms, historically a major challenge of clinical microbiology, gained additional importance in the fields of public health and biodefence. These requirements cannot be well addressed by classical culture-based approaches. Therefore, a wide range of molecular approaches has been suggested. Microarrays are molecular tools that can be used for simultaneous identification of microorganisms in clinical and environmental samples. Main advantages of microarrays are high throughput, parallelism and miniaturization of the detection system. Furthermore, they allow for both high specificity and high sensitivity of the detection. Microarrays consist of set of probes immobilized on a solid surface. Even though the first application of the microarrays can be seen as relatively recent (Schena et al. 1995), the technology developed rapidly reaching the milestone of 5,000 published papers in 2004 (Holzman and Kolker 2004). This development encompasses both the successful transfer of various technological aspects as well as the expansion of the application scope. The most important technological elements of custom-made platforms as well as the characteristics of the commercially available formats are reviewed in this chapter. Furthermore, application potential is presented together with considerations about quality control.