whole
blood (Lahiri & Nurnburger, 1991). The ANKK1/DRD2
markers (rs1800497[Taq1A], rs6277 [C957T], and rs12364283), and the
COMT Val158Met (rs4680) SNP were genotyped using Applied Biosystems
Inc. (AB; LifeTechnologies, Burlington, ON) TaqMan pre-designed assays.
For each reaction, 20 ng genomic DNA were amplified as per
manufacturer's directions scaled to a total volume of 10 μl in an AB
2720 thermal cycler. Post-amplification products were analyzed on the
ABI Prism 7500 Sequence Detection System using the allelic discrimination option, and genotype calls were determined manually by comparing
to six No Template Controls (Grandy, Zhang, & Civello, 1993). The DRD2
rs1799732 [ − 141delC] was genotyped in the same manner using a custom designed TaqMan assay [forward primer: 5′ CAA AAC AAG GGA
TGG CGG AAT C; reverse primer 5′ CCA CCA AAG GAG CTG TAC CT; reporter 1 sequence (VIC): 5′ TAC CCG TTC CAG GCC G; reporter 2 sequence
(FAM): 5′ CTA CCC GTT CAG GCC G].