Microarray layout and design. The microarray contains blocks of probesets for SNP genotyping and CGH. SNP genotyping probesets are composed of two probe quartets, one for each strand (red blowouts). Probes from one quartet typically have hybridization signals in a similar dynamic range. These signals are used to determine a base call and calculate base calling robustness, which is expressed as a Dscore where the two lesser hybridization signals are used to estimate background noise for each probe quartet (grey inset). The CGH probesets record data that are used to generate log2 ratios of a test and reference sample.
Tan et al. Genome Biology 2011 12:R35 doi:10.1186/gb-2011-12-4-r35