One of the main objectives when using 2D-DIGE for
protein expression analysis is the detection of proteins potentially
useful as biomarkers or involved in some path-ways. Since their
appearance the usual techniques to discover differentially expressed
proteins were the use of standard techniques such as fold-changes
and t-test. Neither of them account for non-biological experimental
effects and some ad-hoc techniques where developed and applied
to achieve variance homogenization of the observed data.