Impact of DNA microarray data transformation on gene expression analysis - comparison of two normalization methods.

• DOI: 10.18388/abp.2011_2227
• Publication Date: 2019-03-07T08:03:39Z
• Authors: Marcin T Schmidt; Luiza Handschuh; Joanna Zyprych; Alicja Szabelska; Agnieszka K Olejn...; Idzi Siatkowski; Marek Figlerowicz
• Keywords: Normalization; Database normalization

Two-color DNA microarrays are commonly used for the analysis of global gene expression. They provide information on relative abundance thousands mRNAs. However, generated data need to be normalized minimize systematic variations so that biologically significant differences can more easily identified. A large number normalization procedures have been proposed and many softwares microarray available. Here, we applied two methods (median loess) from packages softwares. were examined using a sample set. We found genes identified as differentially expressed varied significantly depending method applied. The obtained results, i.e. lists genes, consistent only when median methods. Loess implemented in software provided less coherent some probes even contradictory results. In general, our results an additional piece evidence profoundly influence final microarray-based analysis. impact depends greatly algorithm employed. Consequently, procedure must carefully considered optimized each individual