The tRNA Gene DataBase Curated by Experts 'tRNADB CE' was constructed by analyzing 8,342 complete and 86,555 draft genomes of Bacteria and Archaea, 31 complete virus genomes, 845 complete phage genomes, 738 complete plasmid genomes, 121 complete chloroplast genomes, 12 complete eukaryote (Plant and Fungi) genomes and approximately 780 million DNA sequence entries that originated from environmental metagenomic clones. This exhaustive search for tRNA genes from DDBJ/EMBL/GenBank was performed by running tRNAscan SE, a computer program widely used for tRNA gene searches, in combination with ARAGORN and tRNAfinder, to enhance completeness and accuracy of the prediction. Discordance of assignment by these three programs was found for approximately 4 % of the total of tRNA gene candidates. These discordant cases were manually checked by experts in the tRNA experimental field. In addition, tRNA genes of Archaea obtained from SPLITSdb were included.