The September 2009 issue of the National Genealogical Society Quarterly has an article demonstrating the use of DNA to help determine the parentage of a family descended from slaves. The article is called "Virginia Pughs and North Carolina Wests: A Genetic Link from Slavery in Kentucky." NGS members receive the quarterly and can access PDF copies in the members only section of their website but non-members should be able to find a copy of the Quarterly at any good genealogical library.