Quality assessment of gene expression data

With the escalating amount of gene expression data being produced by microarray technology, one of important issues in the analysis of expression data is quality assessment, in which we want to know whether the one chip is artifactually high or low intensity relative to the majority of the chip. We propose a graphical tool implemented in R for visualizing distributions of two gene chips. Moreover, a statistical test based on chi-square test is employed to quantify degrees of array comparability for pairwise comparisons on a large number of arrays.