2.3.Genotyping
Genomic DNA was extracted from peripheral blood leukocytes according to standard procedures using a commercially available kit (E.Z.N.A.TM SQ Blood DAN Kit) following the manufacturer’s instructions. Amplification and extension were carried out on the Veriti® PCR System (Applied Biosystems). The amplified PCR product was purified using the shrimp alkaline phosphatase (Fermentas Life Sciences) and ExoI (New England Biolabs). SNaPshot single base extension of the genetic polymorphisms was performed using ABI Prism® SNaPshot™ Multiplex Kit (Applied Biosystems). The re-purified products underwent capillary electrophoresis in a 96-well plate using an ABI 3730XL Genetic Analyzer (Applied Biosystems). Three SNPs within the CYP2C19 were determined. Detailed SNP and primer information is shown in Supplementary Table 1.