Based on a phylogenomic approach, I plan to resolve the phylogenetic relationships within the eukaryotic supergroups (e.g., excavates, opisthokonts, archaeplastids, SAR etc.). From all these groups, genome and transcriptome data have been collected and browsed for a set of 263 genes whose amino acid sequences will be used to generate a concatenated alignment. Before that, each gene alignment will have to be checked individually in order to remove contaminants or paralogs. For this "decontamination-step", it is necessary to calculate a tree for each single gene. Sequences not of interest can then be recognized by their unexpected branching patterns.