Microarray normalization using Signal Space Transformation with probe Guanine Cytosine Count Correction

Standard expression microarray analysis consists of a number of different steps to enable signal comparisons between experimental conditions. The first step entails normalizing the signal intensity distributions of all probe features on all arrays. A probe feature is a location on the array that contains many copies of the same 25-mer DNA sequence. Normalizing these distributions enables comparison of probe signal between groups. Next, the signal intensities for all probes in a probe set that defines a gene or exon are aggregated into a single value for each array or sample. The aggregate signal value is used to compare gene-level or exon-level expression changes between sample groups or conditions.