The saliva will be transported to GEM Labs, located on MCG campus, by research staff. The genomic DNA will be extracted with the reagent and method supplied by the manufacturer, Oragene. This will be used as the template to amplify the relevant regions of CYP450 2D6 and 2C19. The PCR products will be randomly cleaved into 50 to 100 bp by digestion with DNase I. These fragments will be further labeled with phycoerythrin (PE), a fluorescent dye. The PE labeled fragments will be hybridized to the P450 Roche AmpliChip, washed, and scanned by the Affymetrix automated GeneChip fluidics Station 450Dx and the Affymetrix GeneChip scanner 3000Dx with GeneChip Operating Software Dx 1.1.3. The data will be analyzed by AmpliChip CYP450_US Data Analysis to determine the genotype for 2D6 (it totally assesses 27 mutation sites, deletion, and duplication) and 2C19 (2 mutation sites). Genotyping results will be analyzed by the same software to predict the phenotype (ultra rapid, extensive, intermediate, and poor metabolizer).