Comparison of different collection procedures and two methods for DNA isolation from saliva

Abstract Background: The non-invasive, flexible and easy sample collection makes saliva an interesting source of DNA for research and diagnostic purposes. The aim of our study was to find the most suitable collection method for biological material from the oral cavity and the most effective DNA isolation technique for further analytic applications. Methods: DNA was isolated from swabs, Salivette saliva, whole saliva and samples collected with a commercial set for scraping of buccal cells. Phenol-chloroform extraction and isolation using a silica membrane based commercial kit were compared. Quantity of bacterial and human genomic DNA was estimated using real time PCR. The effects of storage conditions on DNA recovery were assessed. Results: Sample collection techniques significantly affected the quantity of DNA for both, silica membrane based and phenol-chloroform isolations. Whole saliva provided the largest number of bacterial and human genome copies after both extraction methods. Storage for 36 months a...