Design of a protocol for obtaining genomic DNA from saliva using mouthwash: Samples taken from patients with periodontal disease

BackgroundObtaining high quality genomic DNA safely and economically is vital for diverse studies of large populations aimed at evaluating the role of genetic factors in susceptibility to disease.AimThis study was to test a protocol for the extraction of high quality genomic DNA from saliva samples obtained with mouthwash and taken from patients with periodontal disease.MethodsSaliva samples were taken from 60 patients and then stored at room temperature. DNA extraction was carried out at distinct post-sampling times (10, 20 and 30 days). Evaluation of genomic DNA was performed with spectrophotometry, electrophoresis, and PCR genotyping and sequencing.ResultsThe greatest concentration of DNA obtained was 352 μg at 10 days post-sampling, followed by 121.025 μg and 19.59 μg at 20 and 30 days, respectively. When determining the purity of DNA with the spectrophotometric ratio of 260/230, the relations of 1.20, 1.40 and 0.781 were obtained for 10, 20 and 30 days, respectively. In all samples, it was possible to amplify the product of 485 bp and the sequence of the amplicons showed 95% similarity to the reference sequence.ConclusionThe present protocol represents an easy, safe and economical technique for obtaining high quality genomic DNA.