Genetic and Protein Analysis of SIRT1 in Periodontitis

DNA samples were extracted from peripheral venous blood using the DNA salting-out method. Genotyping of all three SNPs was performed using TaqMan^® genotyping assays (Applied Biosystems, Foster City, CA, USA) and SIRT1 (rs3818292, rs3758391, and rs7895833) according to the manufacturer’s instructions using real-time polymerase chain reaction (PCR). Serum SIRT1 levels were determined in 500 control subjects and 201 patients with periodontitis. Serum SIRT1 levels in patients were determined using the commercial enzyme-linked immunosorbent assay (ELISA) kit for human SIRT1 (Human SIRT1 ELISA Kit, Abcam, Cambridge, United Kingdom) according to the manufacturer’s instructions, and optical density was measured immediately at a wavelength of 450 nm, using a microplate reader (Multiskan FC microplate photometer, Thermo Scientific, Waltham, MA, USA). The SIRT1 level was calculated using the standard curve; sensitivity range of the standard curve was 0.63–40 ng/mL, sensitivity 132 pg/mL [21 (link)].