Carcharodon carcharias cDNA 454 sequence reads
Total RNA was isolated by homogenization of heart tissue in TRIzol (Invitogen, Carlsbad, USA) followed by phenol chloroform extraction. Full-length cDNA was synthesized using two sets of oligo dT primers in a two step procedure and single-stranded cDNA was used for hybridization instead of double-stranded (Patanjali et al. 1991). After hybridization, reassociated ds-cDNA was separated from ss-cDNA (normalized cDNA) by hydroxyapatite chromatography. Normalized cDNA was re-amplified using an oligo dT specific primer (L4N).