DNA was prepared from whole blood with standard salting out methods. PER2 rs56013859 was genotyped using the TaqMan MGB biallelic discrimination system. Probes and primers were ordered from and automatically designed by Applied Biosystems using the Assay-by-Design product. PCR reactions were performed in Biometra T1 thermocyclers, and fluorescence results were determined with the use of an ABI Prism 7900HT sequence-detector end-point read. Process and genotyping data were exported into an internal LIM System. Distribution of rs56013859 genotypes was AA = 78.3%, AG = 19.6%, and GG = 2.1% in accordance with Hardy-Weinberg equilibrium (p = .254).
