The Mouthwash: A Non‐Invasive Sampling Method to Study Cytokine Gene Polymorphisms

Background: We describe a simple, non‐invasive mouthwash sampling method for rapid DNA isolation to detect cytokine gene polymorphisms. In the present paper, interleukin‐1β ( IL‐1B ) and interleukin‐1 receptor antagonist ( IL‐1RN ) gene polymorphisms were studied. Methods: Two mouthwash samples and blood samples were collected from 11 healthy individuals. The second mouthwash sample was stored for 7 days at room temperature. Polymerase chain reaction amplification was used to identify a bi‐allelic polymorphism at position +3953 in the IL‐1B gene and a variable number of tandem repeats (VNTR) polymorphism in the IL‐1RN gene. Results: Our results show that the typing of these cytokine gene polymorphisms using DNA isolated from mouthwash samples did not differ from those obtained by a phenol/chloroform isolation method from EDTA anti‐coagulated blood. Moreover, reliable results from mouthwash samples were obtained after storage for at least 7 days at room temperature. Conclusions: Mouthwash can be the method of choice to study gene polymorphisms in periodontitis and other chronic inflammatory diseases. J Periodontol 2000;71:1315‐1318.