Ds cdna synthesis kit

The high throughput brain transcriptome analysis was performed as described previously [7] (link). In brief ten micrograms of total RNA from fetal, surgical and clinical brain samples were used for the cDNA synthesis using ds-cDNA synthesis kit (Invitrogen) according to the manufacturer’s instructions. The resulting ds-cDNA was cleaned and single end tag (SET) sequencing was performed using the Illumina Genome Analyzer per the manufacturer’s instructions. Short read sequences (tags) obtained from the Illumina Genome Analyzer were mapped to the reference HERV mRNAs from the NCBI database (study accession number SRP032168).

Total RNA was isolated from the cell pellet resuspended in TRIzol reagent (Invitrogen, Carlsbad, CA) as described previously [39 (link)]. Each total RNA preparation was treated with RNase-free DNase I (Ambion, Austin, TX) to digest residual genomic DNA and subsequently purified using the RNeasy Mini Kit (Qiagen, Valencia, CA). Total cellular RNA was quantified with a NanoDrop ND-1000 spectrophotometer (NanoDrop Technologies, Wilmington, DE) and RNA quality was assessed with an Agilent Bioanalyzer (Agilent, Santa Clara, CA). Purified RNA of high quality was used as the template to generate ds-cDNA using Invitrogen ds-cDNA synthesis kit (Invitrogen, CA).