RNA samples were purchased from Takara Bio (Palo Alto, CA, USA; Supplementary Material, Table S3). The cDNAs were synthesized using 2–5 µg of total RNA with either cDNA Archive reverse transcription kit (ABI) or Superscript III reverse transcription kit (Invitrogen, Carlsbad, CA, USA), using random primer. cDNA samples were amplified using the GeneAmp XL (rTth DNA polymerase) PCR kit (ABI). The sequences of the human and mouse primers and amplification conditions are listed in the Supplementary Material, Table S4. The DNA sequence was determined by UNC-CH Genome Analysis Facility and compared with the predicted sequence of the 13th exon of the human OPRM1 and human genomic DNA (UCSC database).
