Ent of non-spike-in genes. The PTR method gives the smallest variation for all three normalization algorithms.<p><b>Copyright information:</b></p><p>Taken from "A probe-treatment-reference (PTR) model for the analysis of oligonucleotide expression microarrays"</p><p>http://www.biomedcentral.com/1471-2105/9/194</p><p>BMC Bioinformatics 2008;9():194-194.</p><p>Published online 14 Apr 2008</p><p>PMCID:PMC2375129.</p><p></p