The flow of information through DetectiV is shown in Figure  1 . The basic dataset required is a matrix of data, with rows representing probes on the array, and columns representing measurements from individual microarrays. This dataset is easily produced from data structures created by limma [12] , which includes functions for reading in many common microarray scanner output formats, and affy [13] , which provides functions for reading in affymetrix data. Commonly, researchers will have an additional file of information giving details about each probe. In the case of pathogen detection arrays, this file will most often contain the type, species, genus and other classification data for the pathogen to which each probe is designed. It should be noted that there may be more than one entry in this file for each probe; for example, if a given probe is thought to hybridize to multiple pathogens. In text format, these may be read in using the native read.table command, or in excel format using the RODBC library.