High-yield noninvasive human genomic DNA isolation method for genetic studies in geographically dispersed families and populations.

Human genomic DNA is commonly isolated from peripheral blood samples for genetic studies of families and populations. Blood sampling, however, is expensive and an invasive procedure to which, for ethical reasons, objections may be raised, especially in studies involving older individuals and babies. We have developed a new noninvasive DNA sampling and isolation method involving oral samples taken with cotton swabs. Participants can take mouth swabs themselves, and can send these by mail to the research center, where DNA can be isolated at least up to 3 wks after sampling. DNA isolation from 20 cotton swabs resulted in an average yield of 40{mu}g of high-molecular-weight DNA per individual, sufficient for complete genome searches with {approximately}800 polymorphic DNA markers when using PCR. Compared with blood sampling, which involves clinically trained personnel, this procedure is fast, less expensive, and suitable especially for DNA collection from geographically scattered subjects. 8 refs., 1 fig.