Evaluation of concentration and purity of DNA extracted from mouthwash, saliva and buccal cytobrush samples

Abstract

IntroductionNon-invasive sampling has been highlighted as an alternative sampling for molecular analysis of diseases. Various methods of sampling and DNA isolation have been introduced. This study includes collection of mouthwash, saliva and buccal swab/cytobrush sampling, and extraction using conventional methods. ObjectiveTo assess the DNA quantity and quality by evaluating the concentration and purity of DNA isolated from mouthwash, saliva and buccal cytobrush using in-house DNA extraction methods. MethodsMouthwash, saliva and buccal cytobrush samples were collected from paediatric patients attending monthly blood transfusions in University Malaya Medical Centre. The samples were extracted using alkaline lysis method and purified with phenol:chloroform. The DNA purity and concentration was measured by spectrophotometry. Mean and standard error of mean were calculated and analysed for significance in difference. Results & DiscussionThe DNA with highest purity (1.743 ± 0.031) was obtained from mouthwash samples while DNA with highest concentration (0.796 ± 0.095 μg/μL) was obtained from saliva. Buccal cytobrush samples produced DNA with high purity comparable to mouthwash samples, however, at a lower concentration (0.162 ± 0.041 μg/μL). ConclusionHigh quality DNA can be obtained from mouthwash, saliva and buccal cytobrush samples. Saliva samples may serve as the best alternative sampling for extraction of genomic DNA for its high concentration and acceptable purity.