Preparation of high-density cDNA microarrays. PCR-based cDNA amplification (Hedge et al., 2000 PMID: 10997270) was used to generate DNA from a murine cDNA clone library (Mouse Unigene Set RZPD 2) purchased from the RZPD (http://www.rzpd.de). This murine library contained 21,826 non-redundant clones from diverse tissues. After fully automated PCR-amplification and ultrafiltration-based purification using a Beckman-Coulter cDNA-production unit, control gel electrophoresis was perfomed showing that 95% of the products were clonally amplified. Non clonal or failed PCR-products were excluded from data analysis. The PCR-products were spotted on epoxy-coated glass slides (Schott Nexterion) using the BioRad spotter "Virtek Chip-Writer Pro" with 48 split pins (purchased from Telechem, www.arrayit.com). The arrays were prepared for hybridisation using surface blocking as described by the slide manufacturer.. Keywords = cDNA, microarray, spotted, PCR-products