Abstract: The aim for this project is to establish a fast reliable method for quality based selection of formalin-fixed paraffin-embedded (FFPE) tumor tissue and to determine if the quality of the chosen tissue can be used for global gene expression including DNA micro array. Prior to this six forms of RNA purification methods has been compared to test whether different purification methods would lead to different results. It has been reported by others that increased protein degradation with the enzyme Proteinase K can result in higher RNA concentration as well as superior quality of the purified RNA. In this rapport two kits has been used to examine this hypothesis; MasterPure RNA Purification Kit and Qiagen RNeasy FFPE Kit. It was found that increased protein degradation with Proteinase K (20 hours) does result in higher RNA concentration and quality and also that the Qiagen RNeasy FFPE Kit results in better quality of the purified RNA. In order to examine the possibilities for quality based selection of FFPE tumor tissue the purified samples has been run on the Agilent Bioanalyzer, examined with real-time Q-PCR and finally an attempt has been made to establish the RNA quality of particular samples using a specific PCR assay with Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as endogen control and custom-made primers.