DNA was extracted from saliva samples and amplified by polymerase chain reaction (PCR) using a Perkin Elmer 9700 PCR machine (Applied Biosystems (ABI), Foster City, CA). Primers for the 5-HT2a T102C SNP were 5′-TCTGCTACAAGTTCTGGCTT-3′ (forward) and 5′-CTGCAGCTTTTTCTCTAGGG-3′ (reverse). Primers for the 5-HTTLPR were 5′GGCGTTGCCGCTCTGAATGC-3′ (forward) and 5′-GAGGGACTGAGCTGGACAACCAC-3′ (reverse). The final solution contained 10 mM of deoxyribonucleotide triphosphates (dNTPs), 6 pmol/ul of each primer, 25 mM MgCl2, 1 × mTaqmaster PCR enhancer, and 0.5 μ1 DNA Taq Polymerase (Eppendorf MasterTaq, Brinkman, Westbury, New York). PCR regime included pre-heating at 95 C for 10 minutes, followed by 50 cycles of denaturation at 92 C (15 seconds), annealing at 60 C (60 seconds), and concluding with a final hold at 4 C until stopped by user. For the 5-HT2a T102C polymorphism, T and C alleles were identified by a SNP analysis run on an ABI 7900HT sequence detection system (ABI, Foster City, CA). For the 5-HTTLPR, a fragment analysis assay was run on an ABI 3130 Genetic Analyzer (ABI, Foster City, CA) and a mm1000 marker from Bioventures was used to size the fragments (484-528 base pairs).
